Severe hair loss may be caused by physiological, pathological and physicochemical factors stimulation, etc. Physiological hair loss mainly refers to the loss of hair according to the normal growth cycle, which may vary according to the season and age. Pathological hair loss is commonly caused by excessive secretion of androgens, other endocrine diseases, malnutrition, etc. Physico-chemical stimulation is commonly caused by frequent hair dyeing and certain radioactive stimulation of hair. I. Physiological hair loss: usually people lose 50-100 hairs a day as a normal physiological phenomenon, indicating that the hair is in the natural process of metabolism. Usually in the autumn and winter may appear serious hair loss, mainly due to seasonal temperature changes affect the skin temperature, resulting in hair loss. Usually do not need to deal with, life attention to regular rest and healthy diet can be. Second, pathological hair loss: 1, androgen overproduction: may be due to androgen overproduction resulting in seborrheic alopecia, greasy scalp, itching, increased dandruff and hair loss symptoms. Some people have gradually become more mentally stressed, stay up late, and have irregular living habits, which may lead to endocrine imbalance in the body, resulting in serious hair loss. The hair loss caused by excessive androgens can be treated with ketoconazole lotion, minoxidil tincture and other drugs, and pay attention to regular diet and rest in life and adjust the mentality; 2. Other endocrine diseases: hyperthyroidism, hypothyroidism, polycystic ovary syndrome, anemia, inflammation of hair follicles and other diseases may lead to severe hair loss. For hyperthyroidism, methimazole treatment can be applied, and for hypothyroidism, levothyroxine sodium tablets can be applied. Hair loss due to polycystic ovary syndrome should be treated with the primary disease, and at the same time can be treated with oral anisodone and topical application of minoxidil tincture. Hair loss caused by anemia, should pay attention to the supplementation of iron-rich food to enhance nutrition, such as animal offal, spinach, duck blood, etc., while more vegetables and fruits can be consumed to promote the absorption of iron. Hair loss caused by folliculitis can be treated with topical fusidic acid cream, along with oral minocycline; 3, malnutrition: hair loss caused by lack of some nutrients in the body, such as protein, vitamin B, etc.. Pay attention to a balanced diet, more protein-rich food, such as beef, chicken, eggs, milk, etc., and more vegetables and fruits rich in vitamins and minerals, such as celery, spinach, apples, etc. You should also avoid greasy, spicy, high-sugar diet, as well as moderate exercise. Third, physical and chemical factors stimulation: common chemical factors include frequent perming, hair coloring, the use of substandard shampoo, etc., resulting in hair color change, brittle, and even hair loss. Physical factors are commonly stimulated by exposure to mechanical stimuli or certain radioactive substances, such as X-rays. Therefore, care should be taken to avoid frequent hair coloring and perming damage to the hair, and to purchase regular shampoos for use. If it is unavoidable to contact with radioactive substances, protective measures should also be taken. The above are the main reasons for severe hair loss in life, which should be treated according to the different reasons for hair loss, while cancer patients may also experience severe hair loss during radiotherapy due to the effect of drugs.