Washing your hair twice a day may cause an imbalance in hair oil secretion, hair breakage, damage to the scalp barrier and other hazards. Wash your hair twice a day will over wash away the oil secreted by the scalp, the lack of oil on the skin surface will stimulate the sebaceous gland secretion of the scalp, resulting in an imbalance of oil secretion, the hair is easy to oil fast. Hair washing can not be avoided when the hair pulling, some people’s hair itself is relatively fine and soft, pulling easy to cause hair breakage, serious cases will lead to hair reduction. Hair washing will be the scalp surface oil and dandruff all cleaned off, wash too many times will damage the skin barrier function, causing excessive dry skin, easy to be invaded by external pathogens. It is recommended that usually 2~3 days to wash the head once, oily skin can be appropriate to increase the frequency of cleaning, but should also be maintained in 1~2 days once, it is best to use a mild shampoo to avoid causing irritation or allergy.