Cold and heat in Traditional Chinese Medicine (TCM) are abstract concepts derived from specific phenomena, reflecting the interaction and influence between the human body and the material or environmental conditions. Therefore, understanding cold and heat cannot be based solely on quantitative indicators but should be contextualized within the theoretical framework of TCM.
As an important concept, cold and heat have extensive applications in TCM, serving as symptoms, disease attributes, pathogenic factors, and the four qi (energies) of herbs. However, influenced by modern ways of thinking, there are many misunderstandings regarding the concepts of cold and heat in TCM. This article aims to clarify these concepts.
Pathogenic Cold and Heat
Cold and heat are natural phenomena that cycle with the seasons. When there is excess or deficiency, or when the timing is inappropriate, or when there are sudden changes in temperature, cold and heat can become harmful.
Cold pathogens have a nature of stagnation and contraction, obstructing the meridians, which slows the circulation of qi and blood, leading to pain when there is blockage. They also constrict the qi mechanism, causing muscle and joint stiffness, and can block the pores, preventing sweating. Yin cold can deplete yang qi and can also obstruct yang qi, resulting in a fear of cold.
Heat pathogens, including fire and summer heat, are often referred to as “warm pathogens,” which are a general term for pathogenic qi that can lead to yang-heat diseases. It is commonly said that “heat is the gradual increase of fire, and fire is the extreme of heat,” but it should actually be understood as “heat is the manifestation of fire, and fire is the essence of heat.” In terms of pathogenic characteristics, fire heat is a yang pathogen that easily injures fluids and depletes qi; it tends to rise and can invade the upper parts of the body; it can generate wind, and excessive heat can scorch the liver meridian, leading to internal wind, which manifests as tremors or convulsions. Excessive heat can also cause blood to move recklessly, leading to various forms of bleeding such as hemoptysis or hematochezia. It can disturb the spirit, and during high fever, it can cause delirium. Additionally, the “Lingshu: Abscesses and Sores” states: “Excessive heat causes flesh to rot, and rotting flesh leads to pus.” The “Medical Canon of the Golden Mirror” states: “Abscesses and sores originate from fire toxins, obstructing the qi and blood in the meridians.” Summer heat, on the other hand, is the fire heat of summer, which has a clear seasonal characteristic, tends to injure fluids and deplete qi, and is often accompanied by dampness, presenting a state of high temperature and high humidity.
The constitution formed by both congenital and acquired factors is a relatively stable characteristic inherent in the human body regarding its structural form and functional activities. It manifests as certain differences in response and adaptation to external stimuli in a physiological state, as well as susceptibility to certain pathogenic factors and tendencies in disease progression. The internal environment of cold and heat, such as yang deficiency constitution, yin deficiency constitution, and damp-heat constitution, plays a background role in the nature and evolution of diseases.
Pathomechanism of Cold and Heat
Regarding the cold and heat phenomena in nature, modern explanations state that during different periods of the year, the Earth is in different positions in its orbit, resulting in varying amounts of sunlight and heat received by each region, thus causing seasonal changes and temperature differences. Influenced by the ancient philosophy of the correspondence between heaven and humanity, TCM has long recognized the importance of yang qi in the human body. As stated in the “Suwen: On the Vitality of Heaven and Earth”: “Yang qi is like the sun and the moon; if it loses its place, it will shorten life and not manifest.” Yang qi in the human body can nourish the five organs and six bowels, circulate qi and blood, transform fluids, protect the skin, and resist yin cold, serving as the root of vitality.
TCM believes that the phenomena of cold and heat in the human body are specific reflections of the rise and fall of yin and yang qi. As stated in the “Suwen: On the Correspondence of Yin and Yang”: “When yang prevails, there is heat; when yin prevails, there is cold.” The “Suwen: On Regulating the Menstrual Cycle” states: “When yang is deficient, there is external cold; when yin is deficient, there is internal heat; when yang is excessive, there is external heat; when yin is excessive, there is internal cold.” Specifically, pathogenic yin can lead to the depletion of yang qi or obstruction of yang qi’s movement, or it may be due to a pre-existing deficiency of yang qi, resulting in an inability to warm and transform, which can manifest as cold syndromes. Conversely, pathogenic yang can lead to an excess of yang heat, or it may be due to a deficiency of yin fluids, which cannot restrain yang, resulting in an excess of yang qi, which can manifest as heat syndromes. In other words, whether relative or absolute, an excess of yin qi results in cold, while an excess of yang qi results in heat. Zhang Jingyue insightfully stated: “Cold and heat are transformations of yin and yang.” “When water and fire lose their harmony, it results in cold and heat.”
Symptoms of Cold and Heat
When describing symptoms, cold and heat refer to the sensations of fear of cold and fever. Fear of cold primarily refers to an abnormal sensation experienced by the patient, while fever can be observed as an increase in body temperature or a subjective feeling of heat without a change in temperature. The “Complete Works of Jingyue” lists the inquiry about cold and heat as the first question, serving as two guiding principles for distinguishing the nature of diseases in the eight principles of diagnosis.
Regarding fear of cold, there is a distinction between aversion to cold and fear of cold. Generally, it is believed that if the sensation of fear of cold persists despite adding clothing, covering oneself, or warming by the fire, it is termed aversion to cold, which is often a sign of an exterior syndrome; if it can be alleviated, it is termed fear of cold, reflecting either yang deficiency or yang obstruction. If further differentiated, cold experienced during normal times and throughout the body is often due to yang deficiency, while cold experienced during illness and in specific areas is often due to yang obstruction.
Cold and heat are also direct indicators for assessing the rise and fall of yin and yang. As Zhang Jingyue stated: “Yin and yang are not visible, but cold and heat can be seen.” Generally, when defining the cold and heat attributes of a disease, it is often necessary to consider the deficiency or excess of the disease.
The basic manifestations of cold syndromes include: aversion to cold, fear of cold, cold pain, preference for warmth, a pale and unthirsty mouth, cold limbs curled up, clear and thin phlegm, clear and long urination, loose stools, a pale complexion, a pale tongue with white and moist coating, and a tight or slow pulse. The basic manifestations of heat syndromes include: aversion to heat, preference for cold drinks, a red face and eyes, restlessness, yellow and thick phlegm, hemoptysis, short and red urination, dry and hard stools, a red tongue with yellow and dry coating, and a rapid pulse.
Cold and heat syndromes are fundamentally different yet interrelated; they can appear simultaneously and can transform into one another under certain conditions. In critical stages of disease, there may even be phenomena of false cold or false heat.
Mixed cold and heat syndromes refer to the simultaneous presence of cold and heat symptoms, presenting a phenomenon of alternating cold and heat, which can vary by location, with distinctions between upper and lower, exterior and interior. For example, upper cold and lower heat may present as cold pain in the stomach, vomiting clear phlegm, along with frequent urination, painful urination, and short red urination; upper heat and lower cold may present as heat in the chest, sore throat, and dry mouth, along with abdominal pain relieved by warmth and loose stools. Exterior cold and interior heat may present as aversion to cold, fever, no sweating, headache, body aches, or shortness of breath, along with sore throat, thirst, yellow urination, and constipation; interior cold and exterior heat may present as fever, headache, cough, along with loose stools, clear and long urination, and cold limbs.
Transformations between cold and heat can occur due to internal and external environmental factors. Cold syndromes can transform into heat syndromes, for example, after exposure to cold, one may experience aversion to cold and fever, with no sweating, white coating, and a tight floating pulse, followed by the disappearance of aversion to cold and the emergence of strong heat, restlessness, thirst, yellow coating, and a rapid pulse. Heat syndromes can transform into cold syndromes, for example, after high fever and profuse sweating, one may experience a sudden drop in body temperature, cold limbs, pale complexion, and a weak pulse.
When cold and heat syndromes reach their extremes, there can also be false appearances where true cold resembles heat and true heat resembles cold. True cold with false heat may present as body heat, a flushed face, thirst, a large pulse, yet the desire to cover oneself, thirst for hot drinks but unable to drink much, a face that is intermittently red, a large but weak pulse, and may also present with cold limbs, clear diarrhea, and long clear urination, a pale tongue with white coating. True heat with false cold may present as cold hands and feet, a deep pulse, yet without aversion to cold but aversion to heat, thirst for cold drinks, dry throat, bad breath, short and red urination, dry and hard stools, a red tongue, and yellow and dry coating.
The “Huangdi Neijing” discusses cold and heat with specific names and chapters, such as the “Suwen: On Wind” stating: “Wind qi is stored between the skin and flesh, unable to circulate internally or leak externally… When it is cold, it causes loss of appetite; when it is hot, it consumes muscle, leading to a state of discomfort and inability to eat, known as cold and heat.” The “Lingshu: Cold and Heat Diseases” discusses the symptoms, treatment, and prognosis of cold and heat diseases affecting the skin, muscles, and bones; the “Lingshu: Cold and Heat” discusses the causes, pathomechanisms, and prognosis of scrofula caused by the retention of cold and heat toxins in the meridians.
Medicinal Cold and Heat
The “Shennong Bencao Jing” states that medicines have four qi: cold, heat, warm, and cool. The “Complete Works of Jingyue” points out: “Qi originates from heaven… Warmth and heat are the yang of heaven; cold and coolness are the yin of heaven.” The “Shennong Bencao Jing Shu” also states: “All things must derive from heaven for their growth, and their formation must rely on the earth. Heaven issues commands, governing growth, cold, heat, warmth, and coolness, and the qi of the four seasons flows therein.” In other words, the four qi of medicines are closely related to natural climatic conditions.
The four qi and five flavors of medicines are innate, and their identification process in ancient times could only be completed through “tasting” and “testing,” as stated in the “Shennong Bencao Jing: Record of One Hundred Herbs”: “By tasting, one knows its flavor; by entering the stomach, one knows its nature.” This means that the nature and flavor of a medicine are determined after consumption, using taste and the cold and heat of the disease as reference standards. This is evidently a subjective experience, inevitably influenced by the subjective factors of the perceiver, leading to frequent discrepancies in the judgment of the cold and heat nature of the same medicine. Tao Hongjing lamented: “It is easy to know whether something is toxic or not, but the cold and heat must be clear.”
The difference between cold and cool, warm and hot is merely a matter of degree. Some herbal literature further distinguishes them using terms like great heat, great cold, mild warmth, and mild coolness. However, in essence, the four natures of medicines are fundamentally just cold and heat.
Treatment of Cold and Heat
Cold and heat are manifestations of an imbalance of yin and yang in the body. Diseases have cold and heat, and medicines also have cold and heat. Therefore, the “Shennong Bencao Jing” states: “Treat cold with hot medicines, and treat heat with cold medicines,” meaning to use the cold and heat of medicines to correct the cold and heat of diseases, or “to correct the bias with the opposite.” Regarding this, the “Shennong Bencao Jing: Record of One Hundred Herbs” states: “All medicines… should be used according to their strengths to treat diseases, thus able to supplement the bias and rectify the deficiencies, harmonizing the organs.” The “Jingyue Medical Manuscript” also states: “Use cold medicines to transform the heat of disease, and use hot medicines to transform the cold of disease… This is the principle by which medicines can treat diseases, originating from the yin and yang of the four seasons, embodying the unity of heaven and humanity.”
The treatment principles established in the “Suwen: On the True Essentials” are “treat cold with heat, treat heat with cold.” This belongs to the antagonistic treatment in TCM. When implementing this, attention should be paid to: first, distinguishing between deficiency and excess. Generally, real cold should be warmed and dispersed, while deficient cold should be warmed and tonified; real heat (fire) should be cleared and drained, while deficient heat (fire) should be cleared and lowered. Second, it is essential to distinguish between true and false, as the “Suwen: On the True Essentials” states: “Those who are cold and yet hot should take from yin; those who are hot and yet cold should take from yang.” Wang Bing commented: “Strengthening the master of water to control the yang; benefiting the source of fire to eliminate the yin.” Third, it is necessary to avoid the phenomenon of drug rejection. The “Suwen: On the Great Principles of Governance” proposes a solution: “Treat heat with cold, and take it warm; treat cold with heat, and take it cool.” This means that when using cold medicines to treat heat diseases, they should be taken warm, and when using hot medicines to treat cold diseases, they should be taken cool.
In summary, the concepts of cold and heat in TCM are abstracted from specific phenomena, reflecting the interaction and influence between the human body and the material or environmental conditions. Therefore, understanding cold and heat cannot be based solely on quantitative indicators but should be contextualized within the theoretical framework of TCM.
Note: Specific treatments and medications should follow medical advice!
Copyright Statement:
-
This article is adapted from: China Traditional Chinese Medicine News, Page 4, Author: Zhu Guang
-
Copyright belongs to the relevant rights holders. If there are any improper uses, please feel free to contact us.
-
This public account shares articles and videos for learning, communication, and reference purposes. Non-TCM professionals should not use medicines indiscriminately.