Many women will experience some form of facial hair growth at some point in life. Most chin hair growth is a result of aging or natural hormone changes. Excessive hair growth, however, can be an indication of a hormonal imbalance or more serious problem.
Most girls have a fine facial hair, known as vellus, prior to reaching puberty. As girls reach puberty and begin to produce some male hormones, coarser, darker hair can begin to replace some of the fine hair. This coarse hair is likely to appear above the upper lip and possibly on the chin.
During menopause, lower estrogen levels may change the ratio of male to female hormones. This can cause an increase in chin hair in some women.
Genes play a role in how much facial hair you have. If either of your parents has abundant facial hair, it is likely that you will also be prone to growing hair on the chin. Women from certain ethnic backgrounds such as Middle Eastern, Mediterranean, and South East Asian descent, are more prone to develop facial hair than women of other groups.
Disorders that affect hormone production, such as poly cystic ovaries, can cause excessive hair growth on areas of the face including the chin. If hair growth is excessive or sudden, or accompanied by other changes such as deepening voice or irregular periods, it could be a sign of a hormonal imbalance. Contact a physician if any of these symptoms occur.