The menstrual cycle is under the control of a series of hormones and is necessary for reproduction. An endocrine disease occurs as a result of distubance in one or more of those hormones. Polycystic ovary syndrome (PCOS) is the commonest endocrine condition (15-20%) affecting women of reproductive age. The visualisation of multiple small fluid-filled cysts in the ovaries by ultrasound is known as polycystic ovaries. To make the diagnosis of PCOS, according to published recommendations there must be two out of three of the following criteria:
- Multiple small cysts on one or more ovary. One or more enlarged ovary may also be diagnostic
- Clinical symptoms or blood test evidence of raised levels of androgens (male hormones) such as testosterone
- Irregular periods or evidence of absent or infrequent ovulation.
In PCOS, the cysts may be accompanied by an imbalance of sex hormones, specifically elevated androgens. Normally women have both oestrogens (female hormones) and androgens (male hormones). In PCOS the balance is shifted towards overproduction of androgens. This may lead to acne, fall of scalp hair and/or excessive hair growth on the face and body. Blood test may sometimes show an elevated level of testosterone.
PCOS is often associated with irregular, infrequent or even absent periods. If the periods are irregular, it is unlikely that ovulation is occurring. As a result, women may experience problems conceiving (subfertility).
Women with PCOS may have difficulty controlling their weight. Being overweight makes the symptoms even worse. Conversely weight loss can lead to a dramatic improvement in the full spectrum of symptoms.
Women with PCOS are at increased risk of developing diabetes mellitus because their tissues are resistant to insulin. The prevalence of diabetes in obese PCOS subjects is about 11%. Other possible long-term health problems of PCOS include an increased risk of hypertension (high blood pressure), high cholesterol and cardiovascular disease. These may all be linked to each other. If there are very long gaps between menstruations (periods), there is small increase in the risk of endometrial (lining of the womb) cancer.
Why have I got PCOS?
The exact mechanism is not fully understood yet but there is an underlying resistance to the hormone insulin. Insulin is a hormone produced by the pancreas, which circulates in the blood stream to enable the uptake of sugar by the cells. To compensate for the resistance, the pancreas produces large amounts of insulin. High levels of insulin affect hormone production by the ovary, leading to excess androgens, which disrupt the normal cyclical function of the ovaries. As a result, ovulation may be absent or irregular. It is thought that there may be a genetic reason why some women develop this syndrome. Women with PCOS report female family members with similar symptoms, while the male family members have frontal baldness.