Hair loss at the age of twenty may be caused by physiological factors, but also may be caused by pathological factors, commonly found in seborrheic alopecia, baldness, ringworm, severe psychosomatic diseases and other diseases. It is necessary to clarify the cause of the disease and then carry out targeted treatment, the common treatment methods are general treatment, drug treatment. 1. Physiological factors: under normal circumstances, the human body will fall 50~100 roots per day, usually not more than 100, and accompanied by the growth of new hair, the amount of hair to maintain a dynamic balance, which is a normal physiological phenomenon, do not need to be overly nervous, usually do not need treatment. 2. Pathological factors: (1) Seborrheic alopecia: male patients with seborrheic alopecia can be treated with oral treatment such as low-dose finasteride; female patients can use spironolactone and other medications; and at the same time, topical use of ketoconazole lotion, minoxidil and other medications, to improve the symptoms of hair loss. (2) Patchy baldness: it is a kind of sudden patchy alopecia, hair loss site is limited, the boundary is clear, and the skin lesion site is smooth. It can be treated with minoxidil, glucocorticoid drugs, etc. Phototherapy can also be used under the guidance of doctors. (3) Tinea capitis: often caused by fungal infection, large areas of tinea capitis can destroy hair follicles, leading to severe hair loss. First of all, hair should be shaved, and at the same time, topical antifungal ointment, such as ketoconazole cream, etc.; oral antifungal drugs, such as itraconazole and so on. (4) Serious psychosomatic diseases: Long-term mental stress, anxiety, tension or depression may lead to serious psychosomatic diseases, with symptoms such as diffuse hair loss and dry hair. It is recommended that patients maintain a happy mood, reasonable work and rest, and go to a psychiatrist if necessary. Hair loss at the age of twenty may also be caused by other factors, it is recommended that patients seek medical attention to clarify the cause of the disease, symptomatic treatment, avoid self-medication, so as not to delay the condition.