Polycystic Ovary Syndrome (PCOS)

What it is
Polycystic ovary syndrome (PCOS) is a health problem that can affect a woman's menstrual cycle, ability to have children, hormones, heart, blood vessels, and appearance. The risks of complications from PCOS, such as heart attack, stroke and diabetes, increase as a woman gets older.
About one in ten women of childbearing age has PCOS. It can occur in girls as young as 11 years old. PCOS is the most common cause of female infertility. With PCOS, women typically have:

• high levels of androgens, sometimes called male hormones, although females also make them.
• missed or irregular periods.
• many small cysts, or fluid-filled sacs, in their ovaries.

Causes

The ovaries are two small organs, one on each side of a woman's uterus. A woman's ovaries have follicles, which are tiny sacs filled with liquid that hold the eggs. These sacs also are called cysts. Each month about 20 eggs start to mature, but usually only one matures fully. As this one egg grows, the follicle accumulates fluid in it. When that egg matures, the follicle breaks open to release it. The egg then travels through the fallopian tube for fertilization. When the single egg leaves the follicle, ovulation takes place.

In women with PCOS, the ovary doesn't make all of the hormones it needs for any of the eggs to fully mature. Follicles may start to grow and build up fluid. But no one follicle becomes large enough. Instead, some follicles may remain as cysts. Since no follicle becomes large enough and no egg matures or is released, ovulation does not occur and the hormone progesterone is not made. Without progesterone, a woman's menstrual cycle is irregular or absent. Plus, the cysts make male hormones, which also prevent ovulation.

The cause of PCOS is unknown. Most researchers think that more than one factor could play a role in developing PCOS. Genes are thought to be one factor. Women with PCOS tend to have a mother or sister with PCOS. Researchers also think insulin could be linked to PCOS. Insulin is a hormone that controls the change of sugar, starches, and other food into energy for the body to use or store. For many women with PCOS, their bodies have problems using insulin so that too much insulin is in the body. Excess insulin appears to increase production of androgen. This hormone is made in fat cells, the ovaries, and the adrenal gland. Levels of androgen that are higher than normal can lead to acne, excessive hair growth, weight gain, and problems with ovulation.