What is PCOS?

Polycystic ovary syndrome (PCOS)¹ is a hormonal disorder in women in which the ovaries produce an excess of the male hormone androgen. As its name suggests, PCOS can cause small cysts, or fluid-filled sacs, to form on the ovaries. These cysts produce androgen and can prevent the ovaries from regularly releasing eggs during the menstrual cycle.

Women with PCOS may or may not develop these cysts. However, many women with the condition experience infrequent or prolonged menstrual periods, hormonal imbalances, metabolic problems, acne, and excess body hair growth.

PCOS is a common cause of infertility (the inability to become pregnant). And while it’s not curable, PCOS is treatable. Treatment for PCOS often involves taking medication to help reduce the symptoms of the disorder and prevent further health problems.

How common is PCOS?

Polycystic ovary syndrome is a common health problem: it affects 1 in 10 women of childbearing age². It is also one of the most common causes of female infertility³.

While all women—regardless of race and ethnicity—can develop PCOS, the risk of having the disorder increases if you have a blood relative (such as a mother, sister, or aunt) with PCOS.

PCOS is a lifelong health condition that continues for much longer than just a woman’s childbearing years. While most women are diagnosed with the disorder in their 20s and 30s (often after experiencing problems conceiving), PCOS can occur at any age after puberty⁴.

PCOS causes

The exact cause of PCOS is unknown⁵. However, many women with the disorder are insulin resistant, meaning their bodies can’t properly use the hormone insulin. This causes the hormone to build up in the body, which may, in turn, cause higher levels of androgen—a key feature of PCOS.

Additionally, some women don’t produce enough of the hormones needed for ovulation (the part of the menstrual cycle that occurs when a mature egg is released from an ovary). If ovulation doesn’t occur, the ovaries can develop numerous small cysts, as is seen in PCOS.

Most experts believe that several factors⁶, including genetics, weight, and insulin resistance, play a role in the development of PCOS. Some of these factors include⁷:

• Insulin resistance and excess insulin: Insulin, a hormone produced in the pancreas, helps convert sugars from the food you eat into usable energy. Insulin resistance, which occurs when the body’s cells don’t respond normally to this hormone, can cause blood sugar (glucose) levels to rise and lead to an excess of insulin. Insulin resistance may increase the production of androgen, which causes difficulties with ovulation.

  Many women with PCOS have been found to be insulin resistant—especially those who are overweight and have a family history of type 2 diabetes.

• Excess androgen: Sometimes called “male hormones,” androgens control the development of male traits, such as male-pattern baldness. While all women produce androgens in small amounts, those with PCOS have higher androgen levels than usual. This can prevent ovulation and cause extra hair growth (hirsutism) and acne, all characteristic signs of PCOS.

• Low-grade inflammation: Research has found that women with PCOS have a type of low-grade inflammation (evidenced by the white blood cells’ production of infection-fighting substances). This inflammation stimulates polycystic (cyst-containing) ovaries to produce androgens.

• Weight: Being overweight or obese has been associated with PCOS. However, many women of normal weight have PCOS, and many women who are overweight do not. Ultimately, the relationship between weight and PCOS is not well understood, and experts are not sure whether being overweight causes PCOS or whether having the disorder causes one to be overweight.

• Genetics: Research has suggested that certain genes may be linked to the development of PCOS. Additionally, women who have a blood relative (such as a mother, sister, or aunt) with PCOS or type 2 diabetes have a higher likelihood of developing the disorder than those who do not.

PCOS symptoms

The signs and symptoms⁸ of PCOS usually develop during puberty, around the time a woman has her first menstrual period. While each woman’s signs and symptoms may vary, you must experience at least two of the following to be diagnosed with PCOS:

• Irregular menstrual periods: This is the most common sign of PCOS. Women with the disorder may have infrequent, irregular, missed, abnormally heavy, or prolonged periods.
• Excess androgen: Women with PCOS have higher-than-usual levels of the “male” hormone androgen. This can result in the physical signs of PCOS, such as acne, excess facial and body hair (hirsutism), and, in some cases, male-pattern baldness.
• Polycystic ovaries: Women with PCOS may have enlarged ovaries that contain numerous cysts follicles surrounding the eggs. This can prevent the ovaries from functioning properly.

Other signs and symptoms of PCOS may include⁹:

• Excess body hair, including on the back, chest, and stomach
• Weight gain, especially around the abdomen
• Oily skin and/or acne
• Thinning hair or male-pattern baldness
• Infertility
• Small pieces of excess skin (skin tags) on the armpits or neck
• Dark or thick patches on the back of the neck, in the armpits, or under the breasts

The signs and symptoms of PCOS are usually more severe in women who are obese. If you experience any of these signs and symptoms—especially irregular periods, infertility, or signs of excess androgen—see your healthcare provider.

PCOS in teenagers

Teenagers with PCOS¹⁰ may experience slightly different signs and symptoms than adult women. Because having an irregular menstrual cycle is common within the first few years after starting menstruation (menarche), problems with ovulation may not be immediately apparent in teenage girls.

Rather, ovulation problems are signaled by having irregular periods for more than two years following menarche, having no menstrual cycle for more than three months, or never having had a menstrual period by the time puberty has completed. Additionally, abnormally heavy or frequent periods may also indicate problems related to PCOS.

Adolescent women don’t require an ultrasound to evaluate PCOS, because enlarged ovaries with many follicles develop as part of normal puberty.

Complications from PCOS

Women with PCOS are more likely to develop certain health problems associated with the disorder. Many women with PCOS are insulin resistant¹¹, which increases the risk of type 2 diabetes (and, in turn, related conditions like high blood pressure and heart disease).

Obesity is also associated with PCOS. Women with PCOS who are overweight are at a much higher risk¹² of developing serious health problems as a result of the disorder.

Some complications that may develop as a result of PCOS include¹³:

• Diabetes Type 2 diabetes and prediabetes (a precursor of diabetes) are both associated with PCOS. More than half of women with the disorder develop type 2 diabetes by the age of 40.
• Diabetes during pregnancy: This condition, known as gestational diabetes, occurs when a woman who did not previously have diabetes develops it while pregnant. Gestational diabetes can put the unborn baby at risk and lead to type 2 diabetes later in life for both the mother and baby.
• Infertility: Miscarriage and premature birth are also common complications of PCOS.
• Abnormal uterine bleeding
• Sleep apnea: Sleep apnea, a potentially serious sleep disorder in which breathing repeatedly stops and starts during sleep, has been associated with PCOS. This condition also increases the risk of heart disease and type 2 diabetes.
• High blood pressure (hypertension): High blood pressure, which is commonly associated with diabetes, can damage the heart, brain, and kidneys over time.
• High LDL (“bad”) cholesterol and low HDL (“good”) cholesterol: High cholesterol can also increase the risk of heart disease.
• Heart disease: Women with PCOS are at higher risk of developing heart disease, and their risk increases with age.
• Metabolic syndrome: This syndrome, a cluster of related conditions including hypertension, high blood sugar (hyperglycemia), and abnormal cholesterol or triglyceride levels, significantly increases the risk of cardiovascular disease.
• Stroke: A potentially life-threatening emergency, stroke can occur when plaque (a substance made up of cholesterol and white blood cells) clogs the blood vessels and leads to clots.
• Cancer of the uterine lining (endometrial cancer)
• Nonalcoholic steatohepatitis: A severe liver inflammation caused by the accumulation of fat in the organ.

PCOS has also been linked to depression, anxiety, and eating disorders; however, the connection between these conditions and PCOS is not yet fully understood.