Hirsutism, or excessive hair growth in women in a male pattern, is common and usually benign. It can be caused by polycystic ovary syndrome, which involves irregular periods, obesity, and high androgen levels. Rare causes of hirsutism include late-onset congenital adrenal hyperplasia and ovarian tumors. Treatment options include hair removal methods and medications to lower androgen levels such as combined oral contraceptives or anti-androgens.