The first consideration of hair loss in thirty-year-old men is due to genetic factors, but mental factors, bad habits, etc. may also lead to seborrheic alopecia or baldness in men. 1, genetic factors: mainly seborrheic alopecia, which mostly appears at the age of 20-30. It is manifested by the gradual thinning and loss of hair, starting from both sides of the forehead and gradually extending to the top of the head, or starting from the top of the head and then expanding to the forehead, with hair becoming slender and sparse. Due to the high sebum secretion, some people have greasy hair, and the long-term development of the hair is dry and lusterless; 2, mental factors: often manifested as spot baldness, men appear sudden patchy hair loss, the most important triggers include long-term stress, excessive brain and other neuropsychiatric factors; 3, bad habits: frequent perming and dyeing of hair or long-term frequent washing of hair may lead to hair loss. In addition to the above points, some drug side effects or scalp infection fungus, bacteria, etc. can also lead to hair loss in thirty-year-old men.