Boys navel hair is due to the role of androgens, most of them are a normal physiological phenomenon, a few are pathological phenomena.
1. physiological phenomenon: part of the male body in adolescence androgen secretion is relatively strong, will grow belly hair under the navel, which is the continuation of the distribution of perineal pubic hair, androgen too much will also grow hair in the chest, of course, a part of the people do not grow, this is a normal phenomenon, do not have to be too anxious.
2. Endocrine disorders: If the non-pubertal short period of time under the navel of the hair too much, coarsening, or the whole body in many places to grow thick hair, not except endocrine disorders or androgen secretion, should be to the hospital to check the level of androgen.
If abnormal hair growth occurs, you can go to the hospital to clarify the cause and get timely treatment.