Liver:The liver opens to the eyes; individuals with poor liver and gallbladder function often experience dry, gritty, and dull eyes, with many even “rapidly blinking”. The health of the liver and gallbladder is reflected in the nails; when the liver and gallbladder are healthy, the immune system is strong, and the nails tend to be smooth, shiny, and strong. Otherwise, they may be brittle, prone to breakage, or show signs of fungal infection. Additionally, the liver governs the tendons; prominent veins on the back of the hands indicate poor liver and gallbladder health, and emotionally, individuals may be prone to anger. Some people can become irritable quickly, slamming tables and glaring, often due to excessive liver heat. Those with liver issues tend to prefer sour foods and may have a pale, dull complexion.Heart (Small Intestine):The tongue is the manifestation of the heart. How can we assess heart health through the tongue? A pale, white tongue indicates insufficient heart blood and poor circulation. If there is blood stasis, the tongue may appear dark purple. Ulcerated tongues can indicate excessive heart fire. The face reflects heart health; a normal complexion is rosy and vibrant. A pale, dull face indicates insufficient blood supply to the heart. A dark purple face suggests excessive heart fire and blood stasis. Emotionally, a healthy heart is associated with joy and frequent smiling, even when alone, while a lack of joy may indicate heart issues. Those with heart problems often prefer bitter foods, such as bitter melon, almonds, and grapefruit juice. A red (purple-red) complexion, especially in overweight individuals, often indicates cardiovascular issues.Spleen (Stomach):The spleen opens to the mouth and lips, and its health is reflected in the muscles. Individuals with a healthy spleen and stomach have lips that are light red and glossy, while unhealthy individuals may have pale, white, or sallow lips. This color helps us assess spleen and stomach health. Those with stomach issues often have bad breath, especially those with gastritis or ulcers. The spleen governs the limbs; a healthy spleen and stomach result in strong, toned muscles. Otherwise, the muscles may be weak and flabby. Emotionally, individuals may be overly pensive, often frowning as if they are more worried than necessary, which can be a sign of spleen and stomach issues. Additionally, they may have a sweet tooth (preferring sweeter foods than average) and a yellowish complexion, which can appear waxy, dull, and lacking transparency.Lungs:The lungs open to the nose. The nose is used for breathing, inhaling fresh air and expelling waste. Poor nasal health can affect normal circulation within the body, leading to lung diseases and respiratory issues, which can also trigger nasal inflammation. The skin and hair reflect lung health; when the lungs are weak, the skin and hair become dry, rough, and lack luster, with disordered hair growth and enlarged pores on the face. Emotionally, individuals may experience sadness and worry, often crying without reason. Lin Daiyu from “Dream of the Red Chamber” is a classic example; she suffered from severe tuberculosis, and her tears flowed from spring to autumn and then to winter. Those with lung issues often prefer spicy foods, and their complexion may appear pale, lacking blood color, resembling a white sheet.Kidneys:According to TCM, the kidneys govern the bones and open to the ears, with their health reflected in the hair. Individuals with kidney issues may experience tinnitus and gradual hearing loss. Elderly individuals often show symptoms of deafness, indicating kidney deficiency or decline. The kidneys nourish the bones; some people may feel unwell without any detectable issues at the hospital, which can be attributed to kidney deficiency causing overall weakness. Those with kidney issues often prefer salty foods, have a strong taste for salt, and may be prone to fear and anxiety, indicating poor psychological resilience. A dark complexion (blackish) is common among patients at kidney dialysis centers.A yellowish complexion indicates weak spleen and stomach function; a pale complexion indicates weak lung function; a red complexion indicates weak cardiovascular function; a bluish complexion indicates weak liver and gallbladder function; a dark complexion indicates weak kidney and bladder function. Observing the kidney area is crucial, as the kidneys are the foundation of life. The area from the cheekbones to the ears and down to the jaw is the kidney zone, which is the largest area. The issue of “national kidney supplementation” has become increasingly important due to environmental pollution, which places a heavy burden on the kidneys. If there are moles or spots in this area, it indicates congenital kidney deficiency, which can lead to lower back, leg, and back pain.Deep and large spots in this area may indicate kidney stones. A dark kidney area, or the presence of red blood vessels, acne, or deep crow’s feet, indicates kidney deficiency. If there are moles or spots in the kidney area and deep vertical lines on the forehead, along with a strong preference for salty foods, it suggests a predisposition to hypertension or future cardiovascular diseases. The kidneys govern the bones; when assessing the kidneys, focus on areas of pain. The corners of the mouth represent the shoulders and elbows, while downward indicates the upper and lower limbs. The chin represents areas of pain in the cervical, thoracic, lumbar, and sacral regions. If the chin shows a small dent or “bumps” when the mouth is closed with slight force, ask if they often experience lower back pain; the answer will likely be affirmative. Especially for women, they may experience pain and fatigue before and after their menstrual period.Next, let’s examine the male and female reproductive systems, which are reflected in the philtrum and around the lips. If a man over 40 has a thick upper lip or recurrent acne on the upper lip, along with a particularly round and protruding chin, it indicates a predisposition to prostate enlargement or hypertrophy. If a woman has recurrent ulcers at the corners of her mouth, it may indicate ovarian inflammation or appendicitis. Pale lips in women often indicate anemia or insufficient menstrual flow. If a vertical line appears on the upper lip, it may indicate early menopause and uterine atrophy.If moles or spots are found on the lips, or if the lip line is unclear, it is advisable to undergo a gynecological examination.The bladder’s reflex area is located on both sides of the nose below the philtrum. If this area is red, with red blood vessels, acne, or sores, it indicates cystitis, which may present with symptoms such as dark yellow, frequent, or urgent urination. Cystitis can also cause lower back pain. In women, cystitis may sometimes be due to gynecological issues. If the bridge of the nose is red but there is no frequent or urgent urination, and the entire nasal bridge is red, it may indicate rhinitis.The kidneys open to the ears; if there are deep vertical lines around the ears, it indicates hearing loss. If there are moles, it suggests susceptibility to ear itching, tinnitus, or ear problems, and it is advisable to take “Gu Yuan” (Kidney Tonic). If the earlobes are particularly rosy and translucent, with a pitted nose and red blood vessels in the kidney area, along with a red nose, puffy eyelids, and a red line in the middle of the tongue, it may indicate diabetes or a family history of diabetes. After examining the kidney area, assess the spleen and stomach area, as the stomach is the mother of postnatal life. The tip of the nose represents the spleen, while the wings of the nose represent the stomach. A red nose (rosacea) indicates poor spleen and stomach health. If the spleen is weak, the stomach will also be weak; “nine out of ten people have stomach issues.” If the tip of the nose is red or swollen, it may indicate spleen heat or spleen enlargement, often accompanied by a heavy head, cheek pain, and irritability. If the tip of the nose is yellow or white, it indicates spleen deficiency, which may present with excessive sweating, aversion to wind, lethargy, and lack of appetite. You may notice that many people have rough, dark, or black skin on both sides of the nose, indicating poor stomach health, especially during their youth. If the wings of the nose are red, it indicates stomach fire, leading to hunger and bad breath. If there are red blood vessels and the condition is severe, it is often gastritis. If the wings of the nose are grayish-blue, it indicates stomach cold; when shaking hands, you can feel the person’s fingertips are cold, indicating they may have abdominal pain and diarrhea due to wind-cold. If the wings of the nose are sunken, it often indicates a history of stomach pain, which may lead to atrophic gastritis, increasing the risk of stomach cancer. Poor stomach health can also reflect in lower back pain, lethargy, and lack of energy. If one parent has stomach issues, children under ten are more likely to be hyperactive, have difficulty concentrating in school, and prefer sweet foods. If you now notice a yellow complexion, pale lips, dry skin, and peeling, along with red wings of the nose.Next, observe the liver and gallbladder area, which is represented by the triangular area at the back of the eyebrows (temples) and the middle of the nose. (You may observe that many elderly individuals develop age spots in this area due to liver function decline or disease). The areas on both sides of the nose represent the gallbladder; the liver and gallbladder are interconnected. If the liver is unhealthy, the gallbladder will also be affected. Individuals with gallbladder issues often have spots or growths on both sides of the nose, indicating liver and gallbladder problems. If this area has red blood vessels, acne, or if they wake up with a bitter taste in their mouth, it indicates mild inflammation of the gallbladder; if there are spots, it may indicate cholecystitis. If there are vertical lines in this area or if they smile and form vertical lines, it indicates gallbladder issues. If there are moles or spots in this area, it indicates congenital gallbladder deficiency. Dark circles under the eyes also indicate poor gallbladder health. If both the liver and gallbladder areas are dark or have spots, or if they are uneven, it may indicate fatty liver. If both areas or one of them has acne (bumps), it indicates excessive liver fire, emotional instability, or menopause. If both areas have significant spots and the complexion is dull and unattractive, indicating a lean appearance, it suggests liver disease (hepatitis or cirrhosis).The outer corners of the eyes extending down to the nostrils represent the large intestine system. Why do women develop melasma? One reason is hormonal imbalance, and another is that during pregnancy, the uterus can compress the large intestine, leading to constipation, resulting in toxins being reabsorbed into the body. TCM believes that to maintain beauty, one must first detoxify. “Shun Yi Hang” can help expel a large amount of toxins from the body, allowing many women to regain their beautiful appearance. If this area has red blood vessels, acne, spots, moles, or blemishes, it indicates poor large intestine elimination function, often resulting in dry stools, constipation, or diarrhea. If this area has crescent-shaped spots, it indicates constipation or hemorrhoids. The area where the lower part of the nose meets the outer corner of the eyes is the rectal reflex area; if there are spots here, it indicates hemorrhoids. If this area is red or has white spots, there may be a risk of rectal cancer. The inner side of the large intestine represents the small intestine, which is primarily responsible for absorption. If the spleen and stomach are weak, the small intestine will naturally be affected. If this area has acne, spots, moles, or blemishes, it indicates poor absorption function of the small intestine, often resulting in weakness. The small intestine area may have prominent red blood vessels, which may be caused by low blood pressure or a family history of abnormal blood pressure. Moving up, the area between the eyebrows represents the respiratory system (lungs). If this area has enlarged pores or is red, it indicates respiratory issues. Long-term smokers may develop spots or pigmentation. If the middle of the forehead is sunken and dark, or bluish, or has spots, it indicates lung disease and difficulty breathing; if there are pimples, it indicates recent colds or sore throats. If there are moles or spots between the eyebrows, or if they are white or have prominent lines, it indicates a tendency for pharyngitis, tonsillitis, or chest tightness and shortness of breath, which can also be inherited by their children. Individuals with poor lung function often have poor large intestine elimination function. The upper third of the forehead (hairline) represents the heart system; if this area has acne (bumps) or differs in color from the rest of the face, it indicates psychological stress. If there are spots, it indicates heart disease (such as myocardial weakness); if there are moles or spots, it indicates congenital heart function deficiency. The heart’s reflex area is located on the bridge of the nose between the inner corners of the eyes; if there are horizontal lines or prominent lines, it may indicate arrhythmia or poor heart condition; if the horizontal lines are deep and there are deep vertical lines on the tongue, it may indicate severe heart disease. Individuals with heart disease often have poor small intestine function, which can also lead to vascular, brain, thyroid, and parathyroid diseases. Wrinkles on the lower lip indicate coronary heart disease, while purple lips indicate heart disease. The brain’s reflex area is located between the inner corners of the eyebrows; if there are vertical lines, deep vertical lines, and redness in this area, it indicates insufficient blood supply to the heart and brain, headaches, neurasthenia, vivid dreams, poor sleep, palpitations, and irritability. Dark circles around the eyes indicate insufficient blood supply to the brain or poor sleep and rest. The chest (breast) reflex area is located between the inner corners of the eyes and the bridge of the nose. If this area is dark or bluish in men, it indicates chest tightness and shortness of breath. If this area is dark or bluish in women, it indicates breast tenderness during menstruation. If there are moles or spots on the inner side of the upper eyelids, or if there are pimple-like protrusions when the eyes are closed, it indicates lobular hyperplasia in women or pleurisy in men. If there are small lumps at the corners of the eyes in women, it indicates lobular hyperplasia or breast tumors.TCM uses visual observation to purposefully assess the spirit, color, shape, and state of the patient’s body and local areas to diagnose diseases. This is one of the four diagnostic methods. In clinical practice, observation is combined with listening, questioning, and palpation to comprehensively and systematically understand the patient’s condition and make accurate judgments about diseases.1. Theoretical Basis Observation is a method of diagnosing diseases based on the theories of the organs and meridians. The external body is closely related to the internal organs; if the functions of the organs change, it will inevitably reflect in various aspects of the external body, such as spirit, color, shape, and state. The organs and the body surface are interconnected through the twelve meridians, and they correspond to the body’s tendons, bones, skin, flesh, and pulse (the five bodies): the lungs govern the skin and hair, the liver governs the tendons, the spleen governs the muscles, the heart governs the blood vessels, and the kidneys govern the bones. The five senses are also related to the five organs: the nose corresponds to the lungs, the eyes to the liver, the mouth to the spleen, the tongue to the heart, and the ears to the kidneys. Therefore, observing changes in the body surface and the morphology and function of the five senses can infer changes in the internal organs. It can also reflect the overall vitality of the body. Changes in essence, qi, and spirit are mainly reflected in the head and eyes, and also manifest in the overall body shape, speech, breath, facial color, and even pulse and tongue appearance. Sufficient essence, qi, and spirit indicate health; deficiency in essence, qi, and spirit indicates disease and its causes. Therefore, observation can not only diagnose internal organ diseases but also understand the dynamic changes in the body’s essence, qi, and spirit. 2. ContentIt is divided into overall observation and partial observation. Overall observation focuses on the spirit, color, shape, and state of the entire body, while partial observation uses local changes to understand related pathological changes. In clinical practice, there is no strict distinction between overall and partial observation. In specific steps, overall observation is usually conducted first, followed by orderly partial observation.1. Observing SpiritFocuses on the gaze, facial expressions, and mental activity, which are important for assessing clinical prognosis and life activities. (See Observing Spirit) 2. Observing Facial ColorFocuses on changes in facial color and luster, including the five colors of blue, red, yellow, white, and black, which can reflect changes in the vitality of the organs and the location of pathogenic factors. (See Observing Facial Color) 3. Observing ShapeInvolves diagnosing by observing the patient’s body shape and posture.① Observing Body ShapeFocuses on observing the strength, weakness, and shape of the body and limbs. Body shape characteristics generally reflect the body’s yin-yang and qi-blood constitution; for example, slender individuals often have yin deficiency and yang excess, while short and stout individuals often have yang deficiency and yin excess. Those with balanced body shapes are generally in a state of yin-yang balance. Additionally, body shape can reflect the nature of diseases; for instance, overweight individuals often have phlegm, while thin individuals often have heat.Abnormal body shapes can also have diagnostic significance; for example, a pigeon chest or hunchback often indicates congenital insufficiency or poor nourishment due to kidney essence deficiency or spleen and stomach weakness; a barrel-shaped chest often indicates phlegm accumulation leading to persistent cough and asthma; a distended abdomen with thin limbs indicates ascites.② Observing PostureInvolves observing the patient’s movements, stillness, posture, and actions. For example, trembling of the lips or fingers may indicate heat disease or internal injury; limb spasms, neck stiffness, and arching of the back may indicate convulsive diseases, often seen in liver wind or heat. Abnormal motor function of the hands and feet and various pain symptoms can also be inferred from observing posture. For instance, weak and powerless hands and feet with no pain indicate atrophy; swollen and painful joints indicate obstruction; inability to move the hands and feet, numbness, or stiffness indicate paralysis; holding the abdomen while leaning forward often indicates abdominal pain; holding the lower back while bending over indicates lower back pain, etc. Additionally, observing posture can also help infer the dynamics of yin and yang and the balance of positive and negative factors. For example, curling up while lying down and preferring to be enclosed often indicates yang deficiency and cold; lying down exposed and preferring to be open often indicates yang excess and heat; preferring to lean forward while sitting often indicates lung deficiency; preferring to lean back while sitting often indicates lung excess.4. Observing the Head, Face, Neck, and NapeThe head, face, neck, and nape are where the governing and conception vessels and the three yang meridians of the hands and feet intersect, and the liver meridian also ascends to the head. The brain is the center of mental activity and is governed by the kidneys. The heart governs blood vessels, and the blood vessels nourish the face, so observing the head, face, neck, and nape can provide insights into the vitality of the organs. In fact, observing spirit and color primarily focuses on the head and face.① Observing the HeadThe head being too large or too small often results from congenital developmental issues or insufficient kidney essence. In children, a sunken fontanelle is called a sunken fontanelle, while a delayed closure of the fontanelle is called a cranial defect, indicating congenital insufficiency or empty brain marrow. A bulging fontanelle in children is called a bulging fontanelle, often due to the invasion of warm disease heat, indicating a solid condition. If the head shakes uncontrollably, it often indicates wind disease or insufficient qi and blood. Sparse and dry hair indicates insufficient essence and blood; premature graying in adolescents indicates kidney deficiency and blood deficiency; a tufted appearance in children’s hair indicates malnutrition.② Observing the FaceFocuses on observing facial expressions and color. Other signs, such as facial swelling, indicate edema occurring in the eyelids and face; red, swollen, and painful facial skin often indicates the invasion of wind-heat or fire toxins; facial muscle paralysis may cause facial asymmetry, often due to wind evil invading the collaterals or empty collaterals, commonly seen in yangming meridian diseases.③ Observing the Neck and NapeStiffness in the neck and nape can be a symptom of convulsive diseases, often due to excessive heat or internal wind. Weakness in the head and neck falls under the category of the five soft conditions in children (soft head, soft neck, soft hands, soft feet, and soft muscles), indicating congenital insufficiency and kidney essence deficiency. If there are lumps in the throat area, such as goiter, which may move with swallowing, it often indicates liver qi stagnation and phlegm accumulation, or may be related to local environmental factors.5. Observing the Five SensesThe five senses (eyes, ears, nose, mouth, tongue) are related to the vitality of the organs. Observing changes in the spirit, color, and shape of the five senses can directly diagnose organ diseases.① Observing the EyesThe eyes are the orifice of the liver, and the essence of the five organs and six bowels all converge in the eyes. The related areas of the five organs in the eyes are called the five wheels (see the five wheels and eight structures), so observing the eyes can not only assess spirit but also diagnose organ diseases. Clear and bright eyes with a lively spirit indicate good health; if the whites of the eyes are cloudy, the pupils are discolored, and the spirit is lost, it indicates a more difficult condition. Redness in the corners of the eyes indicates heart fire; pale whites indicate blood deficiency; red whites indicate lung heat; yellow indicates excess damp-heat; swelling indicates liver fire; redness and swelling of the entire eye indicate wind-heat; darkened eye color indicates kidney deficiency. Swelling in the eye socket indicates the initial signs of edema, while sunken eye sockets indicate exhaustion of the internal organs’ essence and qi; protruding eyeballs often indicate goiter. If the pupils change color, or if there are membranes forming in the eyes, it indicates cataracts or other eye diseases. If the pupils dilate, it indicates exhaustion of kidney essence, often seen in critical conditions, or in cases of green wind cataracts and certain poisonings; if the pupils constrict, it often indicates excessive liver and gallbladder fire, or poisoning. Drooping eyelids, known as eyelid droop, indicate congenital insufficiency or deficiency of the spleen and kidneys, and may also result from trauma. If the eyes roll upward or stare straight ahead, it indicates a more serious condition, often seen in children with spleen deficiency or chronic spleen wind.② Observing the EarsThe ears are the orifice of the kidneys and are also where the three yang meridians of the hands and feet converge. Observing the ears primarily involves examining the color, shape, and secretion of the ear lobes.③ Observing the NoseThe nose is the orifice of the lungs and belongs to the spleen meridian, which is connected to the stomach meridian. A blue nose indicates abdominal pain, a yellow nose indicates damp-heat, a white nose indicates blood loss, a red nose indicates heat in the lungs and spleen, and a slightly black nose indicates water retention. A dry nose often indicates yangming heat syndrome. If the wings of the nose are flaring, it initially indicates wind-heat obstructing the lungs, and if prolonged, it indicates insufficient lung qi. Additionally, observing the nose can also provide diagnostic significance for nasal polyps, alcoholic nose, leprosy, syphilis, and other diseases.④ Observing the Mouth and LipsThe spleen opens to the mouth, and its health is reflected in the lips. Healthy lips are rosy, indicating balanced qi and blood and abundant stomach qi. Pale lips indicate blood deficiency, light red indicates cold deficiency, deep red indicates excess heat, and bluish-black indicates qi stagnation and blood stasis. Cracked lips indicate insufficient fluids, while drooling at the corners of the mouth indicates spleen deficiency or stomach heat. Additionally, observing the mouth and lips can provide direct clinical significance for conditions such as stomatitis, oral ulcers, angular cheilitis, and chapped lips.⑤ Observing the TongueThe tongue is the orifice of the heart, and through the meridians, it is directly or indirectly connected to the five organs and six bowels. Observing the tongue primarily involves examining the tongue body and tongue coating. (See Tongue Diagnosis)⑥ Observing the GumsThe kidneys govern the bones, and the teeth are the remnants of the bones. The meridians of the hands and feet converge in the gums. Therefore, observing the teeth and gums can provide insights into kidney and gastrointestinal diseases. This is particularly significant for diagnosing warm diseases. Healthy teeth are white and moist, with firm roots, indicating abundant kidney qi and fluids. If the teeth are dry, it indicates excessive heat damaging fluids; if they are dry and hard as stone, it indicates excessive yangming heat; if they are dry and brittle, it indicates kidney yin deficiency. Loose and sparse teeth, with exposed gums, often indicate kidney deficiency. Pale gums indicate blood deficiency, while receding gums indicate insufficient stomach yin or kidney deficiency; swollen gums indicate stomach fire. Bleeding gums that are painful and red indicate stomach heat, while painless and slightly swollen gums often indicate kidney deficiency or qi deficiency.⑦ Observing the ThroatThe throat is the passage for breathing and eating, related to the lungs and stomach. In healthy individuals, the throat appears light red and smooth, with no obstruction. If the throat is ulcerated and surrounding areas are red and swollen, it often indicates a solid heat condition; if the tonsils are ulcerated and pus forms, it indicates lung and stomach heat. If the throat has ulcerations covered with a white membrane, resembling a white film, it indicates diphtheria. The presence of a tough membrane that is difficult to peel off often indicates diphtheria.6. Observing the SkinThe skin is the body’s exterior, where defensive qi circulates, and it is internally connected to the lungs, playing a role in sweating, temperature regulation, and defending against external pathogens. The essence of the five organs and six bowels circulates through the meridians, supplying qi, blood, and fluids to the skin to maintain its warmth, nourishment, and normal function. Therefore, observing the color and shape of the skin can provide insights into the nature of diseases and the vitality of the organs.① Observing Skin ColorThe principles and methods are similar to observing facial color. Generally, a healthy complexion indicates that the organs’ essence is still strong, and even if ill, it is easier to treat; if the complexion is dry, dull, and lacks luster, it indicates that the organs’ essence is deficient, and the condition is more severe. Diseases that can be effectively diagnosed through skin color include erysipelas and jaundice. If the skin is red as if dyed with pigment, it indicates erysipelas. If the skin appears cloud-like red, with fluctuating or swollen pain, it is called red traveling erysipelas, caused by external wind-heat, excessive heart fire, or fetal toxins in children. If it occurs locally, it is called flowing fire; if the lower limbs are red and swollen, it indicates damp-heat and fire toxins descending; if the facial skin is red and swollen, it indicates wind-heat and toxin invasion. If the skin, face, eyes, and nails appear yellow, it indicates jaundice. Among them, bright yellow like orange indicates yang jaundice, caused by internal damp-heat; dark yellow like smoke indicates yin jaundice, caused by cold dampness obstructing the spleen; if the skin appears yellow with a blackish hue, it indicates black jaundice, caused by blood stasis or kidney deficiency.② Observing Skin ShapeAbnormal skin shapes include swelling, rashes, white spots, and blisters. Swelling in the head, face, chest, abdomen, back, and limbs, with tight skin that sinks upon pressure and does not rise, indicates edema, caused by internal water retention or external skin overflow; if the skin is floating and sinks upon pressure, it indicates qi stagnation. Rashes appear as flat patches on the skin, which are not palpable, and are divided into yang rashes and yin rashes. Yang rashes, also known as eruptive rashes, are large, red or purple, and may even be purple-black, often accompanied by fever, irritability, delirium, thirst, red tongue, and rapid pulse, commonly seen in external warm diseases or heat entering the blood. Yin rashes vary in size, are light red or dark purple, and are hidden and not prominent, appearing and disappearing unpredictably, with patients feeling clear-headed, cold limbs, diarrhea, pale tongue, and thin pulse, often due to internal injury and qi-blood deficiency. The rash emerges from the skin’s blood vessels, appearing as small red bumps, commonly seen in measles and rubella, characterized by small, raised red spots. Generally, rashes that are evenly distributed and sparse, with a rosy color, indicate a mild condition; if they are dense or tightly bound at the roots, with a deep color, it indicates a severe condition. White spots are small, raised bumps on the skin containing fluid, commonly seen in patients with summer heat and dampness, indicating internal dampness and insufficient sweating. Blisters are raised areas of varying sizes containing fluid, seen in conditions like chickenpox, herpes, and eczema. Additionally, there are also signs of skin color changes such as carbuncles, abscesses, boils, and furuncles.7. Observing the Pulse VesselsInvolves diagnosing diseases through changes in the color and shape of the pulse vessels in the hands, fingers, and nails.① Observing the Finger Pulse VesselsAlso known as observing children’s fingerprints, it is mainly used for children under three years old, focusing on the shape, color, thickness, and length of the pulse vessels. The visible and distributed pulse vessels on the palmar side of the child’s index finger can be divided into three sections: wind section, qi section, and life section (see diagram). During the examination, the doctor uses the right thumb to apply moderate pressure from the life section to the qi section and wind section repeatedly, gradually revealing the pulse vessels for observation. Normal pulse vessels are bright red, with a mix of red and yellow, usually appearing slanted and single, with moderate thickness. Dark color indicates severe illness, while light color indicates mild illness; pale color often indicates deficiency, while stagnant color (difficult to push and slow to return) often indicates excess; light red often indicates cold, while dark red often indicates heat; dark purple indicates blood stasis and is critical; blue indicates wind or pain. If the pulse vessels are shallow and visible, it indicates an exterior condition; if they are deep and hidden, it indicates an interior condition. Thickening indicates a solid or heat condition, while thinning indicates a deficiency or cold condition. Gradual growth indicates worsening illness, while shortening indicates improvement. The appearance of pulse vessels in the wind section indicates a mild exterior condition; if it extends to the qi section, it indicates a worsening condition; if it reaches the life section, it indicates deep penetration into the organs, and if it directly reaches the fingertip, it indicates a critical condition.② Observing the NailsThe nails are the remnants of the tendons and are the external signs of the liver and gallbladder. The liver stores blood and governs the smooth flow of qi, so observing the nails can provide insights into the vitality and circulation of qi and blood. Healthy nails are rosy, glossy, strong, and curved, indicating abundant qi and blood and smooth circulation. If the nails are deep red, it indicates heat in the qi level; yellow indicates jaundice, often accompanied by yellow skin; pale white indicates blood deficiency or deficiency of both qi and blood; pale indicates cold deficiency; dark purple indicates blood stasis; and bluish indicates cold conditions. If pressing the nails turns them white, and the color returns slowly, it indicates qi stagnation and blood stasis; if the color does not return, it often indicates blood deficiency. Flat and concave nails are known as spoon nails, often indicating liver blood deficiency; dry nails often indicate liver heat or deficiency of liver blood and heart yin. Thin and brittle nails are often due to qi and blood deficiency, and may also be seen in conditions like wind-heat, nail fungus, and chronic atrophy.③ Observing the Thenar Pulse VesselsThe thenar area is the fleshy part at the base of the thumb, where the hand taiyin lung meridian circulates, and is related to the qi and blood of the stomach. Observing the thenar pulse vessels mainly involves observing color; for example, blue indicates cold, while red indicates heat. This method is currently used less frequently.8. Observing ExcretionsIncludes observing vomit, phlegm, saliva, nasal discharge, sputum, urine, menstrual discharge, pus, and other forms, colors, qualities, and quantities.① VomitClear and thin vomit without odor indicates a cold condition; foul and turbid vomit indicates a heat condition; if undigested food is mixed in with a sour odor, it often indicates food stagnation; if there is clear watery phlegm with dry mouth and no desire to drink, it often indicates phlegm-damp. Vomiting yellow-green bitter water indicates liver and gallbladder damp-heat; if vomiting fresh blood or dark purple clots mixed with food remnants, it indicates stomach heat or liver fire, or blood stasis.② PhlegmYellow, thick, and clotted phlegm indicates heat phlegm; white, clear, and thin phlegm with bubbles indicates wind phlegm; white, clear phlegm with gray-black spots indicates cold phlegm; white, slippery phlegm that is abundant and easy to expectorate indicates damp phlegm; scanty and sticky phlegm that is difficult to expectorate indicates dry phlegm. Phlegm with blood that is bright red often results from yin deficiency with excessive fire, or heat injuring the lung collaterals.③ Nasal DischargeThick nasal discharge indicates external wind-heat, while clear nasal discharge indicates external wind-cold; persistent thick nasal discharge indicates nasal congestion.④ SalivaDrooling at the corners of the mouth that cannot be controlled, with clear and abundant saliva, indicates spleen deficiency; if the saliva is thick and turbid, it indicates spleen and stomach damp-heat; drooling in children may be due to worms or stomach heat. Excessive salivation may be due to cold in the stomach, food stagnation, or kidney deficiency.⑤ Urine and StoolStool resembling sauce indicates heat accumulation in the large intestine; loose stools resembling duck droppings indicate cold deficiency; sticky stools indicate excessive heat injuring fluids; dry and hard stools indicate fluid deficiency, often accompanied by red and white pus indicating dysentery, or undigested food indicating food stagnation or spleen deficiency. Dark yellow and turbid urine, or white urine resembling rice wash, indicates damp-heat descending; clear and long white urine indicates kidney yang deficiency; red and turbid urine indicates blood in the urine.⑥ MenstruationHeavy menstrual flow with thick quality or blood clots, dark red color, often indicates blood heat; if the flow is heavy, thin, and light red, it often indicates qi deficiency; dark menstrual blood with clots often indicates blood stasis; irregular menstrual flow, whether heavy or light, indicates liver qi stagnation.⑦ Vaginal DischargeWomen may have a small amount of white vaginal discharge. If the discharge is excessive or continuous, it indicates a discharge disorder. If the discharge is white, it indicates cold-dampness; if yellow, it indicates damp-heat; if mixed red and white, it indicates liver damp-heat; various colors mixed indicate serious gynecological conditions. If the discharge is clear and thin, it indicates cold deficiency; if thick and sticky, it indicates heat; if it resembles sputum, it indicates spleen deficiency with dampness; if it resembles pus, it indicates internal abscesses.⑧ PusPus is a liquid necrotic substance from skin lesions, often seen in surgical abscesses. If the pus is yellow-white and thick, with bright color, it indicates sufficient qi and blood expelling pathogens; if the pus is yellow-white and thin, with clear color, it indicates a favorable condition; if the pus is yellow and turbid, it indicates excessive internal heat; if the pus is green-black and thin, it indicates deep-seated toxins.(1) Diagnosing Tongue Locations1. Diagnosing Tongue Locations Based on Organ AssociationsThe heart and lungs are located at the top, so the tip of the tongue corresponds to the heart and lungs; the spleen and stomach are in the middle, so the middle part of the tongue corresponds to the spleen and stomach; the kidneys are at the bottom, so the root of the tongue corresponds to the kidneys; the liver and gallbladder are on the sides of the body, so the sides of the tongue correspond to the liver and gallbladder, with the left side belonging to the liver and the right side belonging to the gallbladder. This method is generally used for diagnosing internal injuries and miscellaneous diseases.2. Diagnosing Tongue Locations Based on the Three JiaoBased on the upper, middle, and lower positions of the three jiao, the tip of the tongue corresponds to the upper jiao, the middle part corresponds to the middle jiao, and the root corresponds to the lower jiao. This method is often used for diagnosing external pathogenic changes.3. Diagnosing Tongue Locations Based on the StomachThe tip of the tongue corresponds to the upper stomach, the middle part corresponds to the middle stomach, and the root corresponds to the lower stomach. This method is commonly used for diagnosing gastrointestinal diseases. The various parts of the tongue correspond to the organs, which is one of the current research topics in biological holography. Although there are different interpretations, they all have reference value. In clinical diagnosis, tongue body and coating examinations should be combined, but all four diagnostic methods should be integrated for comprehensive judgment, avoiding overly mechanical adherence.Observing the tongue can be divided into observing the tongue body and the tongue coating. The tongue body, also known as the tongue substance, includes the muscle and vascular tissues of the tongue. Observing the tongue body can be divided into observing spirit, color, shape, and state. The tongue coating is a layer of coating attached to the tongue body, and observing the tongue coating can be divided into observing coating color and coating quality.Normal tongue appearance is referred to as “light red tongue with thin white coating”. Specifically, the tongue body is soft, moves flexibly, and is light red with a bright color; its size is moderate, without abnormal shapes; the tongue coating is thin, white, and moist, evenly distributed, and cannot be wiped away, with roots that are integrated with the tongue body, and the moisture is moderate, neither sticky nor greasy. In summary, the normal tongue appearance is a combination of the basic factors of the tongue body and coating.1. Observing the Tongue Body（1）Tongue SpiritThe tongue spirit is primarily reflected in the luster and liveliness of the tongue body. The key to assessing tongue spirit is to distinguish between vitality and dullness. Vital tongues are moist and vibrant, showing flexibility and a bright color, indicating good health; dull tongues are dry and lack luster, indicating poor health and a poor prognosis. The presence or absence of tongue spirit reflects the vitality of the organs, qi, and blood, and is related to the prognosis of diseases.（2）Tongue ColorColor refers to the color of the tongue body. It can generally be divided into light white, light red, red, dark red, purple, and blue. Except for light red, which is the normal tongue color, the others indicate pathological conditions.① Light Red Tongue:The tongue color is light red, neither too deep nor too shallow, indicating a good flow of qi and blood, suggesting sufficient heart qi and yang qi, thus representing a normal tongue color.② Light White Tongue:The tongue color is lighter than light red, even lacking blood color, referred to as a light white tongue. This indicates a deficiency in yang and a weakened ability to generate blood, leading to insufficient blood circulation in the tongue.③ Red Tongue:The tongue color is bright red, deeper than light red, indicating excessive heat causing qi and blood to surge, thus representing a heat condition. This can be seen in solid conditions or deficiency heat conditions.④ Dark Red Tongue:Dark red indicates a deeper shade than red. This can indicate different diseases based on external and internal factors. In external diseases, it indicates heat entering the blood; in internal diseases, it indicates excessive fire due to yin deficiency.⑤ Purple Tongue:Purple tongues are often caused by poor blood circulation and stasis. Thus, purple tongues indicate diseases, distinguishing between cold and heat. Excessive heat injures fluids, leading to a dry and purple tongue; cold coagulates blood stasis, resulting in a pale purple or blue tongue.⑥ Blue Tongue:The tongue color resembles exposed “blue veins” with no red color, referred to as a blue tongue, often described in ancient texts as resembling a water buffalo’s tongue. This indicates excessive cold and stagnation of yang qi, leading to blood coagulation and stasis.（3）Tongue ShapeRefers to the shape of the tongue body, including age, thickness, swelling, cracks, prickles, and teeth marks. ① Rough Tongue:The tongue body has a rough texture, indicating a rough tongue. Regardless of tongue color or coating, a rough tongue indicates a solid condition.② Delicate Tongue:The tongue body has a delicate texture, with a tender color and often appears swollen, referred to as a delicate tongue, indicating a deficiency condition.③ Swollen Tongue:Swollen tongues can be divided into thick and swollen. A tongue that is larger than normal, even filling the mouth, or has teeth marks, is called a swollen tongue. Swollen tongues often result from phlegm and dampness obstruction; swollen tongues often result from heat toxins or alcohol toxins causing qi and blood stagnation, indicating heat or toxic conditions.④ Thin Tongue:A thin and small tongue is referred to as a thin tongue, often resulting from insufficient qi, blood, and fluids, leading to a lack of nourishment for the tongue. This indicates qi and blood deficiency or excessive fire due to yin deficiency.⑤ Prickly Tongue:Soft papillae on the tongue surface are normal; if the papillae enlarge and protrude, causing discomfort, it is called a prickly tongue, often due to excessive heat.⑥ Cracked Tongue:If there are cracks on the tongue surface without coating, it is called a cracked tongue, often due to deficiency of essence and blood, leading to insufficient nourishment of the tongue. This indicates deficiency of essence and blood. Additionally, about 0.5% of healthy individuals may have deep grooves on the tongue surface, known as congenital tongue fissures, which are covered with tongue coating and do not indicate discomfort, differing from cracked tongues.① Teeth Marks: The edges of the tongue have impressions from the teeth, known as teeth-marked tongue. This often results from spleen deficiency, leading to water retention and causing the tongue to swell, resulting in teeth marks. Therefore, teeth marks are often seen with swollen tongues, indicating spleen deficiency or excessive dampness.（4）Tongue StateRefers to the state of the tongue during movement. A normal tongue state is one where the tongue moves flexibly; pathological tongue states may include rigidity, weakness, elongation, shortening, numbness, trembling, tilting, or protruding.① Rigidity: A tongue that is stiff and rigid, making speech unclear, is called a rigid tongue. This often results from heat disturbing the heart spirit, leading to a lack of control over the tongue, or high fever injuring yin, causing muscle and tendon malnourishment, or phlegm obstructing the tongue collaterals. This is often seen in conditions of heat entering the pericardium, high fever injuring fluids, phlegm obstructing, or as a precursor to stroke.② Weakness: A weak and powerless tongue that cannot extend or retract is called a weak tongue. This often results from extreme deficiency of qi and blood, leading to insufficient nourishment of the muscles. This can be seen in conditions of both qi and blood deficiency, excessive heat injuring fluids, or extreme yin deficiency.③ Elongation: A tongue that extends outside the mouth and is difficult to retract is called an elongated tongue. This often results from relaxation of the tongue muscles due to excessive heat or phlegm disturbing the heart.④ Shortening: A tongue that is tight and cannot extend is called a shortened tongue. This can result from cold coagulating the muscles, leading to retraction; internal phlegm obstruction causing liver wind; excessive heat injuring fluids; or deficiency of both qi and blood, leading to insufficient nourishment and warmth of the tongue. Regardless of whether it is due to deficiency or excess, it indicates a critical condition.⑤ Numbness: A tongue that feels numb and cannot move is called a numb tongue. This often results from insufficient nourishment of the tongue due to qi and blood deficiency. If the numbness occurs without reason and comes and goes, it indicates heart blood deficiency; if the tongue is numb and trembles, or if there are symptoms of stroke, it indicates internal wind.⑥ Trembling: A tongue that trembles and shakes uncontrollably is called a trembling tongue. This often results from deficiency of both qi and blood, leading to insufficient nourishment of the muscles, or excessive heat injuring fluids, leading to wind. This can be seen in conditions of blood deficiency leading to wind or excessive heat leading to wind.⑦ Tilting: A tongue that tilts to one side when extended is called a tilted tongue. This often results from wind evil invading the collaterals or phlegm obstructing the collaterals, but it can also indicate internal wind affecting the organs, leading to relaxation of the tongue muscles on the affected side, causing it to tilt towards the healthy side. This is often seen in stroke conditions or as a precursor to stroke.⑧ Protruding: A tongue that frequently extends outside the mouth is called a protruding tongue; a tongue that licks the lips or moves around the mouth is called a moving tongue. Both are referred to as protruding tongues, often due to heat in the heart and spleen, injuring fluids, leading to frequent movement of the tongue. Moving tongues are often seen in children with developmental delays.2. Observing the Tongue CoatingThe normal tongue coating is produced by the stomach qi, so the vitality of the stomach can be reflected in the changes of the tongue coating. The formation of pathological tongue coating is due to the rise of turbid qi from food stagnation or the rise of pathogenic qi. Observing the tongue coating should focus on both the quality and color of the coating.（1）Coating QualityCoating quality refers to the thickness, moisture, roughness, stickiness, decay, shedding, and root presence of the tongue coating.① Thickness: Thickness is assessed based on whether the tongue body is visible through the coating. If the tongue body is faintly visible through the coating, it is considered thin coating. This is produced by stomach qi and is a normal tongue coating; if seen in disease, it often indicates an early stage of illness or a mild condition. If the tongue body cannot be seen through the coating, it is considered thick coating, often indicating deep-seated pathogenic factors or gastrointestinal stagnation, indicating a more severe condition. If the coating changes from thin to thick, it indicates that the body’s defenses are overwhelmed, and the condition is worsening; if the coating changes from thick to thin, it indicates recovery of the body’s defenses and the expulsion of internal pathogens, indicating improvement in the condition.② Moisture: A moist tongue surface indicates adequate fluids; if it is excessively moist, it feels slippery and may drool, indicating dampness and cold, often seen in yang deficiency with phlegm and water retention. If the tongue appears dry and lacks moisture, it indicates dry coating, often due to excessive heat injuring fluids, or insufficient yin fluids, or dryness injuring the lungs. If the coating changes from moist to dry, it indicates worsening dryness or heat, while a change from dry to moist indicates recovery of fluids and improvement in the condition.③ Decay: If the tongue has coating that suddenly sheds entirely or partially, revealing the tongue body, it is called shedding coating. If the entire coating sheds without regrowth, leaving a smooth surface, it is called mirror tongue or smooth tongue, indicating severe depletion of stomach yin and qi. Regardless of color, this indicates a critical condition. If the coating sheds incompletely, leaving some remnants, it is called mottled shedding coating, indicating both stomach qi and yin deficiency. The transition from having coating to none indicates insufficient stomach qi and yin, and declining vitality; however, if a thin white coating regrows after shedding, it indicates that the pathogens have been expelled and the body’s defenses are recovering, which is a good sign. It is important to note that whether the coating increases or decreases, it should gradually change; if the coating changes suddenly, it often indicates a rapid change in the condition.④ Rooted and Non-rooted Coating: Regardless of thickness, if the coating adheres closely to the tongue surface, appearing to grow from within, it is called rooted coating, also known as true coating; if the coating is not firmly attached and can be easily scraped off, it is called non-rooted coating, also known as false coating. Rooted coating indicates that the pathogenic factors are strong but the stomach qi is not yet depleted; non-rooted coating indicates that the stomach qi has declined. In summary, observing the thickness of the coating can indicate the depth of the disease; observing the moisture can indicate the balance of fluids; observing the roughness can indicate dampness; observing shedding and rootedness can indicate the vitality of qi and yin and the trend of the disease progression.（2）Coating ColorCoating color refers to the color of the tongue coating. It can generally be divided into white, yellow, gray, and black, along with mixed colors, as the coating color is related to the nature of the pathogenic factors. Therefore, observing the coating color can provide insights into the nature of the disease.① White Coating:Commonly seen in exterior conditions and cold conditions. If external pathogenic factors have not yet penetrated deeply, the tongue coating often remains as normal thin white coating. If the tongue is pale with moist white coating, it often indicates internal cold or damp-cold conditions. However, in special cases, white coating can also indicate heat conditions. For example, if the tongue is covered with thick white coating resembling a pile of white powder, it indicates the presence of external pathogenic factors and excessive internal heat, often seen in warm diseases or internal abscesses. If the coating is white, dry, and cracked like sand, it indicates rapid transformation of dampness into heat, with internal heat rising quickly, often seen in warm diseases or improper use of warming tonics.② Yellow Coating:Generally indicates internal conditions and heat conditions. Yellow coating appears due to heat pathogens. Light yellow indicates mild heat, while deep yellow indicates severe heat, and scorched yellow indicates heat accumulation. If the coating changes from white to yellow, it indicates that the exterior pathogens have penetrated and transformed into heat. If the coating is thin and light yellow, it indicates exterior wind-heat or wind-cold transforming into heat. If the tongue is pale and plump with yellow slippery coating, it often indicates yang deficiency with water and dampness not transforming.③ Gray Coating:Gray coating is a light black color. It often develops from dark white coating and can also appear alongside yellow coating. It indicates internal conditions, often seen in internal heat conditions, or cold-warm conditions. Gray coating that is dry often indicates excessive heat injuring fluids, commonly seen in external heat diseases or internal injuries. Gray coating that is moist often indicates phlegm and dampness retention or internal cold obstruction.④ Black Coating:Black coating often develops from scorched yellow or gray coating. Generally, regardless of cold or heat, it often indicates a critical condition. The darker the coating, the more severe the condition. If the coating is black and dry, it may indicate extreme heat and fluid depletion; if it is black and dry, it may indicate intestinal dryness and constipation, or impending gastric failure; if it is found at the root of the tongue, it indicates severe heat in the lower jiao; if it is found at the tip, it indicates self-burning heart fire; if it is black and slippery, with a pale tongue, it indicates excessive internal cold and dampness; if it is black and sticky, it indicates phlegm and dampness obstruction.3. Comprehensive Diagnosis of Tongue Body and CoatingThe progression of diseases is a complex and holistic change process. Therefore, while mastering the basic changes of the tongue body and coating and their associated diseases, it is also essential to analyze the relationship between the tongue body and coating. Generally, observing the tongue body focuses on distinguishing the deficiency and excess of the body’s defenses, which also includes the nature of the pathogenic factors; observing the tongue coating focuses on distinguishing the depth and nature of the pathogenic factors, which also includes the vitality of the stomach. In terms of their relationship, both must be considered together for a comprehensive understanding. In general, changes in the tongue body and coating are consistent, and their associated diseases often reflect a combination of their respective diseases. For example, in internal heat conditions, the tongue is often red with yellow coating and dry; in internal cold conditions, the tongue is often pale with white coating and moist. This is the key to learning tongue diagnosis, but there are also times when their changes are inconsistent, so it is necessary to integrate all four diagnostic methods for comprehensive evaluation. For instance, a white tongue may indicate cold or dampness, but if it is accompanied by a red tongue with dry white coating, it indicates dryness and heat injuring fluids, suggesting that the dryness has transformed into heat quickly, indicating that the condition has progressed; similarly, thick white coating may indicate excessive heat, not necessarily cold; gray-black coating can indicate heat or cold, requiring consideration of the moisture of the tongue body for differentiation. Sometimes, the diseases indicated by the tongue body and coating may contradict each other, but they still need to be observed together. For example, a red tongue with white slippery coating may indicate heat in the nutrient level and dampness in the qi level; in internal injuries, it may indicate excessive fire due to yin deficiency, along with phlegm and food stagnation. This shows that while learning, one can master the distinctions, but in practice, one must conduct comprehensive observations.
