According to the health care theory of traditional Chinese medicine, yin deficiency mainly refers to the loss of body fluids. When the body fluid in the human body is insufficient, the body loses its corresponding moistening and nourishing, so people with yin deficiency constitution show a group of dry and moist symptoms, such as emaciation, reddish complexion, dry mouth, drinking too much water without quenching thirst, etc., all because of the dryness caused by insufficient vaginal fluid in the body. The imbalance of yin and yang in human body, the yin qi in the body can't restrict the yang heat, which leads to the relative prosperity of the yang heat and the internal heat, so the symptoms of virtual fire causing disturbance and restlessness appear. Therefore, people with yin deficiency tend to be extroverted, quick in action and quick in reaction. However, self-control is poor, with physical characteristics such as hyperactivity, hyperactivity, hyperactivity, and impatience and anger. Most people with this kind of physique tendency are usually afraid of heat and like cold, and have strong cold tolerance, and they are easy to be injured by the pathogenic factors of summer heat and yang, and their skin is prone to sores and diseases, and they are also prone to fever. No matter what evil factors such as wind, cold, summer heat and dampness caused by the outside world, they eventually turned into heat syndrome, and symptoms such as dry mouth, thirst, irritability and hyperactivity appeared. If this series of initial symptoms of yin deficiency and excessive fire appear, improper conditioning, or still eating a diet that produces phlegm and gets angry or benefits water, such as onion, ginger, garlic and pepper, or misusing tea to reduce fire, or eating water-saving foods such as adzuki bean and coix seed by mistake, it will aggravate the consumption of vaginal fluid in the body. Different viscera injuries will also have different manifestations: if kidney yin is injured, there will be symptoms such as soreness of waist and knees, dizziness, tinnitus or deafness, nocturnal emission, emaciation, feverish sensation, hot flashes or low fever, night sweats, red cheekbones and yellow urine. If lung yin is damaged, the symptoms are dry lips, dry throat, soft mouth and hoarse voice. If it is not prepared in time, there will be dry cough without phlegm or less sputum, and in severe cases, there will be symptoms of blood in sputum. If you hurt the heart yin, you will be upset, palpitation and insomnia; If you hurt the spleen and yin, you don't want to eat, or the abdominal distension after eating is unbearable; If the stomach yin is injured, it is manifested as hunger in the abdomen but no appetite. This phenomenon was called hunger and no appetite in the ancients. Sometimes it is also manifested as retching and hiccups. If the liver yin is damaged, there will be symptoms of dry eyes and blurred vision. If the damage of the vaginal fluid is too heavy to restrict the yang, then there will be the performance of getting angry and further inflammation, such as pharyngitis, tonsillitis and even pneumonia in the lung, conjunctivitis in the liver and so on. Medicinal tonic and dietary tonic for yin deficiency constitution; Lycium barbarum L. appears in the list of medicinal and edible animals and plants promulgated by the Ministry of Health. Black sesame and mulberry, which we often eat in our daily life, are also classified as yin-tonifying drugs in pharmacology. Other common Radix Adenophorae, Rhizoma Polygonati Odorati, Lily, Polygonatum sibiricum, Fructus Ligustri Lucidi, Carapax et Plastrum Testudinis, and Carapax Trionycis are also traditional Chinese medicines for nourishing yin. In addition, the tremella, sea cucumber and pigskin we often eat also have a good effect of nourishing yin, so eating more of these foods in the dry season of autumn can prevent the loss of vaginal fluid in the body and enhance the resistance to external dryness. The causes leading to yin deficiency in constitution are not only related to fever or chronic consumptive diseases caused by congenital endowment deficiency and some exogenous pathogens, but also directly related to the consumption of diuretics. For example, adzuki bean, Coix lachryma, tea, lotus leaf and wax gourd peel all have the function of promoting diuresis and reducing swelling, so people with yin deficiency constitution should not eat them. Many people like to use this kind of diuretic drugs to lose weight, and they can indeed lose weight by reducing the water in the body. However, when using this kind of food to lose weight, the body is prone to the above-mentioned yin while losing weight. Traditional Chinese medicine terms of yang deficiency. Refers to the pathological phenomenon of yang deficiency and decline. Yang can warm the limbs and viscera. If Yang is deficient, the function of the body will decrease, and it is easy to show signs of deficiency and cold. Common ones are Wei Yang deficiency, Spleen Yang deficiency and Kidney Yang deficiency. The main symptoms of yang deficiency are chills, cold limbs, pale complexion, thin stool, long urine, weak pulse and so on. Yin deficiency constitution should avoid yang deficiency constitution should eat warm food, food with the function of warming yang and dispelling cold, food with high calorie and rich nutrition. Avoid eating cold things, all kinds of cold drinks, and all kinds of cold fruits. The five major symptoms of yang deficiency constitution are chills and cold, and the limbs are not warm, which are the most important symptoms of yang deficiency. Yang is like the sun in nature. Without it, the internal environment will be in a "cold" state. When the grain is not digested, it means that the stool is mixed with undigested food. The ancients had an image metaphor for this phenomenon. The digestion of food is like cooking raw rice into cooked rice, the stomach is like a pot for cooking, and the yang is like a fire for cooking. Without fire, rice cannot be cooked into rice. Therefore, when the yang is insufficient, the food entering the stomach cannot be well "decomposed" (digested) and directly discharged from the intestine. Lack of spirit and yang deficiency, cell life activities decline, so it is characterized by listlessness and laziness. The consumption and metabolism of water in the body with a light and fat tongue or teeth marks depend on the transpiration of yang. If the yang is weak and the transpiration consumption of water and liquid is insufficient, excess water will accumulate in the body, resulting in fat tongue. The tongue is fat, and teeth marks appear when it is squeezed by teeth. The pulse condition is thin and the yang is insufficient, so the pulse condition is thin and weak. The symptom of yang deficiency constitution "yang qi" can resist the influence of bad weather on human body. Yang deficiency constitution is vulnerable to cold and humidity, causing diseases of joints, muscles and other tissues; Yang deficiency constitution has low immune function, and it is easy to catch a cold, or other diseases occur, and the condition does not heal repeatedly; Insufficient heat production of yang deficiency constitution leads to vasoconstriction, blocked circulation and insufficient blood supply to the brain for a long time, which is easy to lead to brain function decline and then brain atrophy; Decreased digestive function of constitution can easily lead to chronic diarrhea, dyspepsia, malnutrition, anemia, or edema, etc. Physical reproductive system function decline, easy to lead to infertility. The food yang deficiency constitution that recuperates yang deficiency constitution should focus on tonifying yang qi. The following foods are suitable for the recuperation of yang deficiency constitution. For example: venison, mutton, dog meat, beef, milk, goat's milk, broiler, goose, sparrow, shrimp, eel, swim bladder, pepper, leek, garlic, ginger, glutinous rice, black rice, coix seed, sweet potato, yam, euryale seed, lentil, maltose, longan, glutinous rice.