Multiple, small, fluid-filled cysts in the ovaries associated with a sex hormone imbalance
Many women (up to about a quarter) have multiple fluid-filled cysts in their ovaries but most of these women do not have polycystic ovary syndrome (PCOS), which is the presence of multiple ovarian cysts associated with an imbalance of the sex hormones and certain other characteristics, such as acne, excessive body hair (see Virilization), and menstrual irregularities. The sex hormone imbalance, which may include higher than normal levels of the male sex hormone testosterone, may prevent ovulation (egg release), thus reducing fertility (see Female infertility).
The underlying cause of PCOS is not fully understood but the increased resistance of body tissues to the hormone insulin that is a feature of the syndrome is thought to play an important part. To compensate for the increased insulin resistance, the pancreas produces excessive insulin, which, in turn, may lead to overproduction of testosterone, high levels of which disrupt normal functioning of the ovaries. PCOS sometimes runs in families.
The symptoms vary in severity, depending on the degree of hormone imbalance. PCOS may go unnoticed until a woman is tested for infertility. Symptoms include:
Infrequent or absent periods (see Amenorrhoea).
Excessive hair growth on the face, around the nipples, and/or on the lower abdomen.
Thinning of the hair on the head.
If your doctor suspects that you have PCOS, he or she will take blood samples to measure your levels of sex hormones. You will also have ultrasound scanning to look for ovarian cysts.
Treatment depends on the severity of your symptoms and whether you want to conceive. Infertility can be treated with drugs, such as clomifene (see Drugs for infertility). If drugs are unsuccessful, the cysts may be treated with diathermy (a type of heat treatment) carried out during laparoscopy. If necessary, assisted conception may then be considered. If you do not want to have children, abnormal periods can be treated with a combined oral contraceptive pill.
To treat insulin resistance, if necessary, and reduce your risk of developing diabetes, you may be prescribed an antidiabetic drug (see Drugs for diabetes mellitus), such as metformin. Such drugs may also restore ovulation and regulate your menstrual periods. If you are overweight, losing weight may help to relieve symptoms of PCOS. Excess hair can be removed by electrolysis.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.