Polycystic ovarian syndrome (PCOS, polycystic ovary syndrome) is a relatively common hormonal disorder that causes a number of different symptoms in women of reproductive age. Common to all women with PCOS is an irregularity in the menstrual cycle and the presence of excess male hormones (androgens).
The condition was named because of the finding of enlarged ovaries containing multiple small cysts (polycystic ovaries). Although most women with PCOS have polycystic ovaries, some affected women do not.
PCOS has also been referred to as Stein-Leventhal syndrome and polycystic ovarian disease (PCOD).
It is a problem with hormones that affects women during their childbearing years (ages 15 to 44). Between 2.2% to 26.7% of women in this age group have PCOS.
Many women have PCOS but don’t know it. In one study, up to 70% of women with PCOS hadn’t been diagnosed.
It 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 number 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.
It 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.
What causes PCOS?
The exact cause is not known. Most experts think that several factors, including genetics, play a role:
High levels of androgens
Androgens are sometimes called “male hormones,” although all women make small amounts of androgens. Androgens control the development of male traits, such as male-pattern baldness. Women with PCOS have more androgens than normal.
Higher than normal androgen levels in women can prevent the ovaries from releasing an egg (ovulation) during each menstrual cycle, and can cause extra hair growth and acne, two signs of PCOS.
High levels of insulin
Insulin is a hormone that controls how the food you eat is changed into energy. Insulin resistance is when the body’s cells do not respond normally to insulin. As a result, your insulin blood levels become higher than normal.
Many women with PCOS have insulin resistance, especially those who have overweight or obesity, have unhealthy eating habits, do not get enough physical activity, and have a family history of diabetes (usually type 2 diabetes). Over time, insulin resistance can lead to type 2 diabetes.
Common symptoms of PCOS
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 symptoms are:
- Irregular periods – A lack of ovulation prevents the uterine lining from shedding every month. Some women with PCOS get fewer than eight periods a year
- Heavy bleeding – The uterine lining builds up for a longer period of time, so the periods you do get can be heavier than normal
- Hair growth – More than 70% of women with this condition grow hair on their face and body — including on their back, belly, and chest. Excess hair growth is called hirsutism
- Acne – Male hormones can make the skin oilier than usual and cause breakouts on areas like the face, chest, and upper back
- Weight gain – Up to 80% of women with PCOS are overweight or obese
- Male-pattern baldness – Hair on the scalp gets thinner and fall out
- Darkening of the skin – Dark patches of skin can form in body creases like those on the neck, in the groin, and under the breasts
- Headaches – Hormone changes can trigger headaches in some women
How PCOS affects your body
Studies have found links between PCOS and other health problems, including:
- Diabetes. More than half of women with PCOS will have diabetes or prediabetes (glucose intolerance) before the age of 40.4 Learn more about diabetes on our Diabetes page
- High blood pressure. Women with PCOS are at greater risk of having high blood pressure compared with women of the same age without PCOS. High blood pressure is a leading cause of heart disease and stroke. Learn more about heart disease and stroke
- Unhealthy cholesterol. Women with PCOS often have higher levels of LDL (bad) cholesterol and low levels of HDL (good) cholesterol. High cholesterol raises your risk of heart disease and stroke
- Sleep apnea. This is when momentary and repeated stops in breathing interrupt sleep. Many women with PCOS have overweight or obesity, which can cause sleep apnea. Sleep apnea raises your risk of heart disease and diabetes
- Depression and anxiety. Depression and anxiety are common among women with PCOS
- Endometrial cancer. Problems with ovulation, obesity, insulin resistance, and diabetes (all common in women with PCOS) increase the risk of developing cancer of the endometrium (lining of the uterus or womb).
How PCOS is diagnosed
Doctors typically diagnose PCOS in women who have at least two of these three symptoms:
- high androgen levels
- irregular menstrual cycles
- cysts in the ovaries
Your doctor should also ask whether you’ve had symptoms like acne, face and body hair growth, and weight gain.
A pelvic exam can look for any problems with your ovaries or other parts of your reproductive tract. During this test, your doctor inserts gloved fingers into your vagina and checks for any growths in your ovaries or uterus.
Blood tests check for higher-than-normal levels of male hormones. You might also have blood tests to check your cholesterol, insulin, and triglyceride levels to evaluate your risk for related conditions like heart disease and diabetes.
An ultrasound uses sound waves to look for abnormal follicles and other problems with your ovaries and uterus.
Pregnancy and PCOS
PCOS interrupts the normal menstrual cycle and makes it harder to get pregnant. Between 70% to 80% of women with PCOS have fertility problems.
This condition can also increase the risk for pregnancy complications.
Women with PCOS are twice as likely as women without the condition to deliver their baby prematurely. They’re also at greater risk for miscarriage, high blood pressure, and gestational diabetes.
However, women with PCOS can get pregnant using fertility treatments that improve ovulation. Losing weight and lowering blood sugar levels can improve your odds of having a healthy pregnancy.
Diet and lifestyle tips to treat PCOS
Treatment for PCOS usually starts with lifestyle changes like weight loss, diet, and exercise.
Losing just 5% to 10% of your body weight can help regulate your menstrual cycle and improve PCOS symptoms. Weight loss can also improve cholesterol levels, lower insulin, and reduce heart disease and diabetes risks.
Any diet that helps you lose weight can help your condition. However, some diets may have advantages over others.
Studies comparing diets for PCOS have found that low-carbohydrate diets are effective for both weight loss and lowering insulin levels. A low glycemic index (low-GI) diet that gets most carbohydrates from fruits, vegetables, and whole grains helps regulate the menstrual cycle better than a regular weight loss diet.
A few studies have found that 30 minutes of moderate-intensity exercise at least three days a week can help women with PCOS lose weight. Losing weight with exercise also improves ovulation and insulin levels.
Exercise is even more beneficial when combined with a healthy diet. Diet plus exercise helps you lose more weight than either intervention alone, and it lowers your risks for diabetes and heart disease.
Common medical treatments
Birth control pills and other medicines can help regulate the menstrual cycle and treat PCOS symptoms like hair growth and acne.
Taking estrogen and progestin daily can restore a normal hormone balance, regulate ovulation, relieve symptoms like excess hair growth, and protect against endometrial cancer. These hormones come in a pill, patch, or vaginal ring.
Metformin (Glucophage, Fortamet) is a drug used to treat type 2 diabetes. It also treats PCOS by improving insulin levels.
One study found that taking metformin while making changes to diet and exercise improves weight loss, lowers blood sugar, and restores a normal menstrual cycle better than changes to diet and exercise alone.
Clomiphene (Clomid) is a fertility drug that can help women with PCOS get pregnant. However, it increases the risk for twins and other multiple births.
Hair removal medicines
A few treatments can help get rid of unwanted hair or stop it from growing. Eflornithine (Vaniqa) cream is a prescription drug that slows hair growth. Laser hair removal and electrolysis can get rid of unwanted hair on your face and body.
Surgery can be an option to improve fertility if other treatments don’t work. Ovarian drilling is a procedure that makes tiny holes in the ovary with a laser or thin heated needle to restore normal ovulation.
Can I still get pregnant if I have PCOS?
Having PCOS does not mean you can’t get pregnant. It is one of the most common, but treatable, causes of infertility in women. In women with PCOS, the hormonal imbalance interferes with the growth and release of eggs from the ovaries (ovulation). If you don’t ovulate, you can’t get pregnant.
Your doctor can talk with you about ways to help you ovulate and to raise your chance of getting pregnant.
See your doctor if
- You’ve missed periods and you’re not pregnant
- You have symptoms, such as hair growth on your face and body
- You’ve been trying to get pregnant for more than 12 months but haven’t been successful
- You have symptoms of diabetes, such as excessive thirst or hunger, blurred vision, or unexplained weight loss
If you have PCOS, plan regular visits with your primary care doctor. You’ll need regular tests to check for diabetes, high blood pressure, and other possible complications.