1) physiological factors: ① mental factors, irregular life, overwork, lack of sleep, and physical consumption greater than intake will all cause physical emaciation. 2 Dietary factors, dieting and even anorexia will lead to thinner and thinner bodies; Some oral abnormalities can also affect eating, such as toothache caused by wisdom teeth and braces.

(2) Pathological factors: ① Gastrointestinal factors, such as chronic gastritis, peptic ulcer, chronic nonspecific colitis, intestinal parasites, gastrectomy, abnormal eating after cholecystectomy, and weakened digestion and absorption function, make the body thinner and thinner. Metabolic diseases, such as hyperthyroidism, are mainly manifested as high metabolic syndrome such as fear of heat, hyperhidrosis, polyphagia, hunger and emaciation; Diabetes, emaciation, thirst, polyuria and other symptoms. ③ Consuming diseases, such as AIDS, chronic fever, active tuberculosis, chronic liver disease, etc. 4 Malignant tumors, such as those of the liver, gastrointestinal tract and pancreas, can lead to weight loss.