Yin deficiency refers to the pathological phenomenon of deficiency of substances such as essence, blood, or body fluids. Since essence, blood, and body fluids all belong to Yin, it is termed Yin deficiency. This condition is often seen in patients who have suffered from prolonged illness or after febrile diseases that lead to the internal consumption of Yin fluids. In modern society, due to increased mental strain, many office workers experience Yin deficiency. For instance, many people who stay up late are found to have a high incidence of Yin deficiency. I have encountered numerous office workers who go to bed after midnight, and many of them exhibit signs of Yin deficiency. On one occasion, I visited a foreign enterprise and found a high proportion of employees with Yin deficiency, likely related to excessive mental strain. Additionally, diet can also lead to Yin deficiency. I have seen many women who enjoy spicy hot pot or barbecued food suffer severely from Yin deficiency. This may be acceptable in Sichuan, but consuming such foods in dry Beijing could harm Yin due to their spicy nature.
So, how do we determine if someone has Yin deficiency? In Traditional Chinese Medicine (TCM), we primarily assess symptoms. There is a saying, “Yin deficiency leads to internal heat“. Due to insufficient body fluids, Yin deficiency cannot control fire, leading to symptoms such as five hearts heat (palms and soles feeling hot), afternoon tidal fever, night sweats, flushed cheeks, weight loss, dry mouth and throat, a desire for cold drinks, yellow urine, dry stools, and a red tongue with little coating. Among these, five hearts heat refers to the sensation of heat in the palms and soles, and some people even feel the need to stick their palms against a cool wall to feel comfortable. The term ‘five hearts’ includes the four hearts (palms and soles) plus the heart itself, leading to feelings of irritability and heat, hence the term five hearts heat.
Afternoon tidal fever means that the fever comes in a rhythmic manner, typically not felt in the morning but starting in the afternoon, which is characteristic of Yin deficiency heat. Night sweats are well-known, referring to sweating during sleep, and in severe cases, the pillow and sheets may become soaked. Daytime sweating is termed self-sweating. Among these symptoms, the most significant indicator is a red tongue with little or no coating, with the red tongue being the primary sign. Additionally, the pulse may be thin and rapid, which may be difficult for some to identify, but it indicates that the pulse is slightly faster than normal.
Yin deficiency can be further categorized into various organ deficiencies. For example, lung Yin deficiency is characterized by insufficient lung Yin, leading to internal heat. This is often caused by prolonged coughing that damages Yin or by the later stages of febrile diseases that injure body fluids. The specific manifestations include dry cough with little or sticky phlegm, dry mouth and throat, weight loss, afternoon tidal fever, five hearts heat, night sweats, flushed cheeks, and in severe cases, blood-streaked phlegm, hoarseness, a red tongue with little moisture, and a thin rapid pulse. Another example is heart Yin deficiency, which presents with insomnia, vivid dreams, palpitations, forgetfulness, irritability, night sweats, five hearts heat, dry mouth and throat, a red tip of the tongue, little coating, and a thin rapid pulse. There may also be flushed cheeks, irritability, dizziness, and other symptoms of internal heat. These conditions are often seen in individuals with chronic liver and kidney insufficiency, true Yin deficiency, or those who have not recovered from the later stages of febrile diseases. In modern society, due to high work pressure, excessive thinking can deplete heart blood, leading to heart Yin deficiency. Insufficient Yin blood fails to nourish the heart and calm the spirit, resulting in palpitations, insomnia, vivid dreams, and forgetfulness. Internal heat from Yin deficiency manifests as night sweats, irritability, heat in the palms and soles, dry mouth and throat, a red tip of the tongue, little coating, and a thin rapid pulse. Flushed cheeks and dizziness are also symptoms of internal heat.
Another example is stomach Yin deficiency, which refers to insufficient stomach Yin. This can be caused by chronic stomach diseases, the later stages of febrile diseases where body fluids have not been replenished, excessive consumption of spicy foods, or emotional distress leading to Qi stagnation and heat that injures stomach Yin. The main manifestations include dull pain in the stomach area, lack of appetite, dry mouth and throat, dry stools, or a feeling of fullness in the stomach, or nausea, a red tongue with little moisture, and a thin rapid pulse.
In modern society, spleen Yin deficiency is particularly important. This refers to insufficient spleen Yin, leading to inadequate nourishment and weak transformation. It is often caused by external warm diseases that deplete Yin fluids, or individuals who are constitutionally Yin deficient, or emotional distress leading to liver Qi stagnation that burns Yin fluids, or excessive consumption of spicy foods, or the inappropriate use of warming and drying herbs. Based on my observations, it seems that the excessive use of hormones in the rearing of meat animals has led to many meat-loving individuals, especially children, often having spleen Yin deficiency, possibly because these hormones are heat-inducing and can harm Yin. The manifestations of spleen Yin deficiency include reduced appetite, a preference for meat, bland taste, post-meal bloating, weight loss, fatigue, little saliva, dry lips, bright red lips, five hearts heat, dry stools, short and red urine, a red tongue with dry thin coating or no coating, and a thin rapid pulse. Such children are often very active, some cannot stay still, and may even have a volatile temper.
Another example is liver Yin deficiency, which refers to the loss of Yin fluids, leading to the liver being unable to moisten and control Yang, resulting in internal heat disturbance, primarily manifested as dizziness, dry eyes, rib pain, and irritability. This is also known as liver deficiency heat syndrome. Specific manifestations of liver Yin deficiency include dizziness, dry eyes, reduced vision, or dull pain in the ribs, facial flushing or redness in the cheeks, or twitching of the hands and feet, dry mouth and throat, five hearts heat, tidal fever, night sweats, a red tongue with little coating, a thin rapid pulse, and an irritable temperament.
Lastly, kidney Yin deficiency refers to insufficient kidney Yin, leading to weakened nourishing and moistening functions. This can be caused by constitutional Yin deficiency, prolonged illness damaging the kidneys, excessive sexual activity, febrile diseases harming Yin, or the excessive consumption of warming and drying substances. Clinical manifestations include dizziness, tinnitus, weakness in the lower back and knees, hair loss, loose teeth, insomnia with vivid dreams, tidal fever, night sweats, five hearts heat, dry throat, flushed cheeks, a red tongue with little moisture, and a thin rapid pulse. In men, there may be nocturnal emissions, while women may experience scanty menstruation or amenorrhea.
So, how should individuals with Yin deficiency generally adjust their condition?
First, dietary control is essential. Individuals with Yin deficiency should consume more cooling and nourishing foods, favoring sweet, cool, moistening, and Yin-nourishing foods, as well as fresh vegetables and moistening fruits. They should avoid spicy and stimulating foods, warming and drying foods, fried or roasted items, foods that are excessively hot, and foods high in fat. Below are some recommended foods for individuals with Yin deficiency:
Duck: It nourishes Yin and benefits the stomach. The “Compendium of Materia Medica” states: “Nourishes Yin and eliminates steaming heat.” Renowned Qing Dynasty physician Wang Mengying noted in his “Dietary Records of Suixi Residence” that duck meat “nourishes the Yin of the five organs, clears the heat of deficiency, and nourishes the stomach and generates fluids.” It is commonly believed that duck is the ideal nourishing food for those with Yin deficiency. Recently, I reviewed the dietary records of Emperor Qianlong and found that duck dishes were particularly frequent in his meals, almost daily. He lived to be eighty-nine years old, the longest-lived emperor in history, and his attention to dietary nourishment was likely a significant factor.
Pork (skin): Pork has the effect of nourishing Yin and moistening dryness. Qing Dynasty physician Wang Mengying observed that blacksmiths, despite working in extreme heat, remained healthy because they consumed soup made from lean pork. He concluded that pork has the characteristic of nourishing Yin, stating: “Pork nourishes kidney fluids, replenishes stomach juices, nourishes liver Yin, and moistens the skin, stopping thirst.” The “Essentials of Materia Medica” states: “Pork has a rich flavor, nourishes the intestines and stomach, generates body fluids, and moistens the skin.” Therefore, it is suitable for those with Yin deficiency, with pork skin being even more effective. Zhang Zhongjing created the pork skin soup to moisten the throat and relieve dryness, which is the beginning of this idea.
Eggs: They not only benefit Qi and nourish blood but also have the effect of nourishing Yin and moistening dryness, whether from egg whites or yolks. In the past, some Yin-nourishing herbal formulas would include an egg after cooking, as TCM believes that egg yolk has Yin-nourishing properties.
Pears: They have the effects of generating fluids, moistening dryness, and clearing heat, making them particularly suitable for those with lung Yin deficiency or those who have suffered from febrile diseases that have harmed Yin. The “Compendium of Materia Medica” states: “The cooked ones nourish the Yin of the five organs.” The “Chongqing Tang Essays” states: “For warm and dry diseases, and for Yin deficiency with fiery heat, the juice can be effective.” In old Beijing, there is a dessert made from autumn pears, which is prepared with some Yin-nourishing herbs, and it can effectively nourish Yin and moisten dryness. Generally, supermarkets in northern China sell it, and regardless of the season, it can be consumed when experiencing Yin deficiency. Additionally, in the past, when prescribing remedies to moisten the lungs and stop coughing, some old TCM practitioners would suggest adding sliced snow pears to the decoction for the same effect.
Mulberries: They have the function of nourishing Yin and replenishing blood, particularly beneficial for nourishing the Yin of the liver and kidneys. Ming Dynasty physician Miao Xiyong wrote in the “Shennong’s Materia Medica” that it is “a medicine for cooling blood, replenishing blood, and benefiting Yin,” and also stated, “Thirst due to internal heat and insufficient body fluids can be alleviated by generating fluids, as all five organs belong to Yin, and benefiting Yin can benefit all five organs.” Especially for those with liver and kidney Yin deficiency who experience thirst, dim vision, and tinnitus, consuming mulberries is most suitable. Recently, while traveling by plane, I was pleasantly surprised to see mulberry juice offered among the beverages, as mulberries are delicious and easy to find when in season. However, they are hard to find out of season, so having a drink made from them is beneficial for preservation.
Goji Berries: They have the function of nourishing Yin and benefiting essence, especially for those with kidney and liver Yin deficiency who experience lower back pain, dizziness, blurred vision, tinnitus, or those with lung Yin deficiency who have tidal fever, night sweats, or cough due to deficiency. During the Republic of China, renowned physician Zhang Xichun noted that he would place a bowl of water by his bedside at night and find that most of it was gone by morning. He then started eating goji berries before bed and found that he no longer felt thirsty at night, demonstrating their Yin-nourishing and moistening effects.
Bird’s Nest: It is neutral in nature, sweet in taste, and has the function of nourishing Qi and Yin, especially beneficial for lung Yin. It is an excellent nourishing food. Individuals with Yin deficiency, particularly those with lung Yin deficiency such as tuberculosis, bronchiectasis, pulmonary atrophy, elderly bronchitis, and chronic bronchitis, should consume it. Qing Dynasty physician Zhang Lu stated that it can “nourish deficiency and treat cough with red phlegm.” Wu Yiluo said: “Bird’s nest greatly nourishes lung Yin, replenishing and clearing.” The “New Compendium of Materia Medica” also records that it “greatly replenishes original Qi, moistens the lungs, and nourishes Yin.” Nowadays, there is much debate about bird’s nest, especially regarding modern scientific analyses of its simple composition and lack of nutrition. Coupled with issues of counterfeiting, bird’s nest has almost lost its former glory. However, this is unnecessary, as bird’s nest is an excellent food-medicine product, which is indisputable. I noted in the dietary records of Emperor Qianlong that he frequently consumed bird’s nest, with several dishes made from it daily, often combined with duck. The imperial physicians would not have used something useless so frequently for the emperor. A close friend once gifted me a box of bird’s nest drink, and after my mother consumed it, she asked me why her skin had become so smooth and radiant recently. After much thought, I realized it was due to this drink, as there were no other significant dietary changes, highlighting the nourishing effects of bird’s nest. As for the issue of counterfeiting, it is a societal problem in China and not related to the bird’s nest itself.
White Fungus: It has the effects of nourishing Yin, benefiting the stomach, and generating fluids. White fungus is rich in nutrients and is a commonly used nourishing food, especially suitable for those with lung and stomach Yin deficiency.
Ejiao: It can both nourish blood and nourish Yin. The “Compendium of Materia Medica” states: “Ejiao primarily nourishes blood and fluids. For those with insufficient Yin, it can be supplemented with flavor, as the sweetness of Ejiao nourishes Yin blood.” It is particularly suitable for individuals with lung and kidney Yin deficiency. I have previously discussed the effects of Ejiao in earlier blog posts, which you can refer to.
Recommended Reading: Liu Duzhou on Phlegm-Damp Disease
This article is reproduced from the WeChat public account “Mingyi Open Class”. The original text is from Dr. Luo Dalun’s Sina blog. Compiled and published by Mingyi Open Class.
