Polycystic Ovary Syndrome (PCOS): Symptoms, Causes, and Treatment
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What is PCOS?
Causes
Symptoms
Health effects
Diagnosis
Pregnancy and PCOS
Diet and lifestyle
Medical treatments
When to see a doctor
The bottom line
Introduction

Polycystic ovary syndrome (PCOS) is a condition that affects a woman’s hormone levels.

Women with PCOS produce higher-than-normal amounts of male hormones. This hormone imbalance causes them to skip menstrual periods and makes it harder for them to get pregnant.

PCOS also causes hair growth on the face and body, and baldness. And it can contribute to long-term health problems like diabetes and heart disease.

Birth control pills and diabetes drugs can help fix the hormone imbalance and improve symptoms.

Read on for a look at the causes of PCOS and its effects on a woman’s body.


What is PCOS?
PCOS is a problem with hormones that affects women during their childbearing years (ages 15 to 44). Between 2.2 and 26.7 percent of women in this age group have PCOS (1, 2Trusted Source).

Many women have PCOS but don’t know it. In one study, up to 70 percent of women with PCOS hadn’t been diagnosed (2Trusted Source).

PCOS affects a woman’s ovaries, the reproductive organs that produce estrogen and progesterone — hormones that regulate the menstrual cycle. The ovaries also produce a small amount of male hormones called androgens.

The ovaries release eggs to be fertilized by a man’s sperm. The release of an egg each month is called ovulation.

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) control ovulation. FSH stimulates the ovary to produce a follicle — a sac that contains an egg — and then LH triggers the ovary to release a mature egg.

PCOS is a “syndrome,” or group of symptoms that affects the ovaries and ovulation. Its three main features are:

cysts in the ovaries
high levels of male hormones
irregular or skipped periods
In PCOS, many small, fluid-filled sacs grow inside the ovaries. The word “polycystic” means “many cysts.”

These sacs are actually follicles, each one containing an immature egg. The eggs never mature enough to trigger ovulation.

The lack of ovulation alters levels of estrogen, progesterone, FSH, and LH. Estrogen and progesterone levels are lower than usual, while androgen levels are higher than usual.

Extra male hormones disrupt the menstrual cycle, so women with PCOS get fewer periods than usual.

PCOS isn’t a new condition. Italian physician Antonio Vallisneri first described its symptoms in 1721 (3Trusted Source).

SUMMARY
Polycystic ovary syndrome (PCOS) affects up to almost 27 percent of women during their childbearing years (4). It involves cysts in the ovaries, high levels of male hormones, and irregular periods.

What causes it?
Doctors don’t know exactly what causes PCOS. They believe that high levels of male hormones prevent the ovaries from producing hormones and making eggs normally.

Genes, insulin resistance, and inflammation have all been linked to excess androgen production.

Genes
Studies show that PCOS runs in families (5).

It’s likely that many genes — not just one — contribute to the condition (6).

Insulin resistance
Up to 70 percent of women with PCOS have insulin resistance, meaning that their cells can’t use insulin properly (7Trusted Source).

Insulin is a hormone the pancreas produces to help the body use sugar from foods for energy.

When cells can’t use insulin properly, the body’s demand for insulin increases. The pancreas makes more insulin to compensate. Extra insulin triggers the ovaries to produce more male hormones.

Obesity is a major cause of insulin resistance. Both obesity and insulin resistance can increase your risk for type 2 diabetes (8).

Inflammation
Women with PCOS often have increased levels of inflammation in their body. Being overweight can also contribute to inflammation.