Hirsutism is the term used for excessive hair growth in women. It refers to a male pattern of hair, i.e. in the moustache and beard areas, or occurring more thickly than usual on the limbs. There may be hairs on the chest or an extension of pubic hair on to the abdomen and thighs. What is considered normal for a woman, and what is considered hirsute, depends on cultural factors and race. Hirsutism is very common. Hirsutism is nearly always genetic in origin. In families where hirsutism is normal, both female and male relatives may have more hair than average.

Although some women with hirsutism have increased amounts of male hormones (e.g. DHEA or testosterone), most have normal levels. The problem in these women is that the hairs are more sensitive than normal to small amounts of hormone. The hairs grow more quickly and thicker in response to it. The increased growth is usually first noted in late teenage years and tends to gradually get more severe as the woman gets older. If it occurs either with or without acne after hormone use, it is a sign of elevated DHEA or testosterone levels.

Blood, saliva or urine tests may be arranged to make sure that the hirsutism is not due to excessive male hormone levels. An ultrasound examination of the ovaries may be necessary as one common cause of hirsutism is polycystic ovaries.