Hair loss at the age of 20 may be due to mental factors, androgenetic alopecia, baldness and other causes, patients should take appropriate treatment measures for the cause of the disease, such as vitamin supplements, medication, physical therapy and so on. 1. Mental factors: patients should learn to release their own pressure, reduce the late night, and at the same time to maintain balanced nutrition, eat more light food, avoid eating too spicy, stimulating, greasy food, pay attention to supplement the B vitamins, which are beneficial to the growth of hair. 2. Androgenetic alopecia: patients should first inhibit androgen secretion, men can take oral finasteride, women can take oral spironolactone, and then apply 5% or 2% minoxidil solution at the hair loss place to promote hair growth. If the above methods cannot improve hair loss, patients can also go to the hospital for hair transplantation. All of the above medications should be used under the guidance of a doctor. 3. Patchy baldness: patients can use topical glucocorticoid or minoxidil solution, or take oral or injected glucocorticoid, immunosuppressant and other drugs, such as hydrocortisone, cyclosporine and so on. Or it can be treated by physical therapy such as ultraviolet irradiation, photodynamic therapy, excimer laser and so on. Patients should refer to the advice of the competent doctor to choose the appropriate treatment plan. The above are some specific treatments for severe hair loss at 20 years old, which need to be selected according to the specific situation of the patient to choose the appropriate treatment plan. No matter which kind of medicine is used, you must go to the hospital to consult the doctor for a detailed examination before using it.