The presence or absence of armpit hair is partly determined by congenital factors, and some people are born without armpit hair, which does not affect their health. If the absence of armpit hair is caused by shaving or epilation, we should be alert to the occurrence of skin ulcer and infection, or skin allergy and other hazards. 1. skin breakout infection: if the patient in the process of shaving armpit hair damage to the local skin, then the local skin breakout may be combined with bacteria and other pathogens infection. 2. Skin allergy: due to the strong irritation of hair removal creams, for allergic or sensitive skin, it may cause local skin erythema, pimples, accompanied by obvious itching of the skin. At the same time for adolescent women, due to the role of androgens, the body gradually appear axillary hair, pubic hair growth, if the female body hair does not grow significantly, be alert to the occurrence of endocrine disorders, if necessary, need to go to a regular hospital gynecology consultation, improve the sex hormones and other related examinations, clear cause of the disease and then active treatment.