Hirsutism - Classification of Causes
Hirsutism can often be accounted for by ethnicity or genetics, but in a small percentage of people it can be a sign of underlying disease. It is thought that the fundamental problem may be an increase in resistance to insulin which drives the ovaries to produce testosterone. This, in turn, will have secondary effects on hair growth.
The most common underlying medical condition associated with hirsutism is likely polycystic ovarian syndrome (PCOS), which affects between 1% and 4% of all women of child-bearing age. PCOS is characterized by:
- Menstrual abnormalities or amenorrhea
- Polycystic ovaries
Other known causes include:
- Androgen-producing tumours (ovarian or adrenal)
- Congenital adrenal hyperplasia, which is a disorder that involves a deficiency of an enzyme involved in the synthesis of cortisol and/or aldosterone.
- Cushing's disease, which occurs when your body is exposed to high levels of the hormone cortisol for a long period of time.
- Drugs, and hormones such as anabolic steroids, and a medicine called danazol, which is used to treat endometriosis, can all induce hirsutism. Other medications associated with increased hair growth include phenytoin (Dilantin™), minoxidil (Loniten®, Rogaine®), and diazoxide (Proglycem™). Some "Natural" supplements such as dehyroepiandrosterone (DHEA) and androstenedione may also cause hirsutism.
- Idiopathic hirsutism refers to excessive hair growth that is non-androgen dependent. It affects women who have regular menstrual cycles and normal levels of androgen.
- Familial (genetic) hirsutism is not associated with excessive levels of androgen. It runs through families and is common in some ethnicities including women of Middle Eastern origin.