Boys have hair under the navel, belongs to a normal physiological phenomenon, with the body androgen secretion level, may also be related to genetic factors.
1. Androgen secretion level: relatively speaking, the male body androgen secretion level is higher than that of women, so male body hair is relatively thicker and denser than that of women.
2. Influence of genetic factors: The growth rate, color and shape of hair are all influenced by genes, so for those who have many body hairs in their family, the chances of their children having more body hairs will be higher.
Since body hair is a normal tissue structure and has certain physiological functions, it is generally not necessary to do too much treatment.