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.
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, 2 ).
Many women have PCOS but don’t know it. In one study, up to 70 percent of women with PCOS hadn’t been diagnosed ( 2 ).
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 ( 3 ).
Summary
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 ( 7 ).
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. Studies have linked excess inflammation to higher androgen levels ( 9 ).
Summary
Some women start seeing symptoms around the time of their first period. Others only discover they have PCOS after they’ve gained a lot of weight or they’ve had trouble getting pregnant.
The most common PCOS symptoms are:
- Irregular periods.
- Heavy bleeding.
- Hair growth.
- Acne.
- Weight gain.
- Male-pattern baldness.
- Darkening of the skin.
- ·Headaches.
Summary
Having higher-than-normal androgen levels can affect your fertility and other aspects of your health.
Infertility
To get pregnant, you have to ovulate. Women who don’t ovulate regularly don’t release as many eggs to be fertilized. PCOS is one of the leading causes of infertility in women (12).
Metabolic syndrome
Up to 80 percent of women with PCOS are overweight or obese ( 13 ). Both obesity and PCOS increase your risk for high blood sugar, high blood pressure, low HDL (“good”) cholesterol, and high LDL (“bad”) cholesterol.
Together, these factors are called metabolic syndrome, and they increase the risk for heart disease, diabetes, and stroke.
Sleep apnea
This condition causes repeated pauses in breathing during the night, which interrupt sleep.
Sleep apnea is more common in women who are overweight — especially if they also have PCOS. The risk for sleep apnea is 5 to 10 times higher in obese women with PCOS than in those without PCOS (14).
Endometrial cancer
During ovulation, the uterine lining sheds. If you don’t ovulate every month, the lining can build up.
A thickened uterine lining can increase your risk for endometrial cancer (15).
Depression
Both hormonal changes and symptoms like unwanted hair growth can negatively affect your emotions. Many with PCOS end up experiencing depression and anxiety (16).
Summary