Polycystic ovary syndrome (PCOS) is a condition in which a woman has an imbalance of female sex hormones. This may lead to changes in the menstrual cycle, cysts in the ovaries, trouble getting pregnant, and other health problems.
Polycystic ovaries; Polycystic ovary disease; Stein-Leventhal syndrome; Polyfollicular ovarian disease; PCOS
PCOS is linked to changes in hormone levels that make it harder for the ovaries to release fully-grown (mature) eggs. The reasons for these changes are unclear. The hormones affected are:
- Estrogen and progesterone, the female hormones that help a woman's ovaries release eggs
- Androgen, a male hormone that is found in small amounts in women
Normally, one or more eggs are released during a woman's cycle. This is known as ovulation. In most cases, this release of eggs occurs about 2 weeks after the start of a menstrual period.
In PCOS, mature eggs are not released. Instead, they stay in the ovaries with a small amount of fluid around them. There can be many of these. However, not all women with the condition will have ovaries with this appearance.
These problems with the release of eggs can contribute to infertility. The other symptoms of this disorder are due to the hormone imbalances.
Most of the time, PCOS is diagnosed in women in their 20s or 30s. However, it may also affect teenage girls. The symptoms often begin when a girl's periods start. Women with this disorder often have a mother or sister who has similar symptoms.