Long anal hair is a normal physiological phenomenon, may also be caused by excessive secretion of androgen. 1. Physiological phenomenon: Whether male or female, with the arrival of puberty development stage, the anus, pubic area and armpit will begin to grow hair, which is a very normal physiological phenomenon, anal hair will increase the air permeability of the anus. Everyone will grow, but the length of each person’s anal hair varies. 2. Androgen secretion: If the anal hair grows very long, need to consider and endocrine relationship, if the patient’s body androgen secretion is relatively more, will stimulate the growth of hair, resulting in the anus, armpit and pubic parts of the hair relative to other people to be denser, and also longer. To summarize, if you find that the anal hair is too long, affecting the anal cleanliness, it is best to consult the anorectal department for medical treatment, and it is necessary to carry out the appropriate treatment or therapy, as well as relieving their own worries.