Buzhong Yiqi is a term of TCM syndrome differentiation, and it is one of the treatment methods of "tonifying, purging, clearing away heat and dispersing". Buzhong Yiqi is to regulate the spleen and stomach. The spleen and stomach and other viscera have the physiological functions of promoting digestion, resolving turbidity, ascending and descending turbidity. Also known as the qi of spleen and stomach. Sometimes, it only refers to the function of spleen governing ascending Qing. The function of spleen and stomach produces middle qi, which in turn supports the qi of spleen and stomach.

A method of treating qi deficiency syndrome with traditional Chinese medicine. Also called invigorating qi. This is a supplementary method. Qi deficiency syndrome is often caused by eating disorders, old age, infirmity, long illness, etc., and clinically shows the symptoms of decreased visceral function. According to the characteristics of clinical manifestations of different viscera-qi deficiency syndromes, different methods of invigorating qi can be adopted, such as invigorating lung qi, spleen qi, heart qi and kidney qi.

Ginseng, Codonopsis pilosula, Astragalus membranaceus, Atractylodes macrocephala, Dioscorea opposita and other drugs are commonly used to form prescriptions. Representative prescriptions include Bufei Decoction, Sijunzi Decoction, Buzhong Yiqi Decoction and Shenqi Pill. We should pay attention to the following two points when using the method of invigorating qi in clinic: ① Stomach fullness caused by dizziness due to liver fire, hyperactivity of liver yang, obstruction of collaterals by phlegm, food retention or obstruction of collaterals by dampness. This method is not suitable for use. ② Qi deficiency combined with pathogenic excess, and the method of supplementing qi should be combined with the method of eliminating pathogenic factors.

Yiqi: refers to the method of treating qi deficiency syndrome with Yiqi drugs. Lung governs qi, and qi governs the qi of internal organs; Shui Gu is absorbed by the spleen and stomach of middle energizer, and the spleen is healthy, so qi deficiency is mostly related to lung and spleen. Supplementing qi refers to a therapeutic method of invigorating qi. Suitable for lung qi deficiency, symptoms such as lack of qi, laziness, rapid breathing, pale face, fear of wind and spontaneous sweating. Deficiency of spleen qi is manifested as abdominal distension, mental fatigue, loss of appetite and diarrhea. Commonly used drugs such as Radix Codonopsis, Radix Astragali, Rhizoma Atractylodis Macrocephalae, Radix Glycyrrhizae, etc.

There are generally two specific manifestations of regulating spleen deficiency. First, the spleen and stomach are weak, the face is sallow and dull, the body is tired and weak, the body is emaciated, anorexia or refusal to eat, or the stool has indigestible residues, the stool is not shaped, it is easy to sweat, and it is easy to catch a cold again and again. Second, spleen-yin deficiency, qi-blood imbalance, abdominal distension, even worse after eating, no or little coating, and thready pulse. Yupingfeng powder can be used to tonify Wei Qi, consolidate exterior and astringe sweat; Using Sijunzi Decoction and Buzhong Yiqi Decoction to tonify middle qi is helpful to health.