Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS), also known as polyendocrine metabolic ovary syndrome (PMOS), is a group of symptoms caused by a hormonal imbalance. The symptoms affect metabolism, the menstrual cycle, reproductive health, heart and blood function, inflammatory responses, and other characteristics. 

Overview

Polycystic ovary syndrome (PCOS), also known as polyendocrine metabolic ovary syndrome (PMOS), is a group of symptoms caused by a hormonal imbalance.

Women with PCOS usually have at least two of the following three symptoms:

  • Absence of ovulation (when the ovary does not release a mature egg), leading to irregular periods or no periods at all
  • High levels of hormones called androgens, or signs of high androgens, such as increased body or facial hair
  • Growths in one or both ovaries, often clumps of ovarian follicles that have stopped developing
  • Absence of or irregular ovulation

PCOS is the most common cause of infertility when women are not ovulating. Many women do not find out they have PCOS until they have trouble getting pregnant.

Signs and Symptoms

The symptoms of PCOS are wide-ranging. Often, women and healthcare providers may not suspect PCOS because the symptoms may seem unrelated.

Menstrual irregularities may include:

  • No menstrual periods, called amenorrhea
  • Skipped periods, called oligomenorrhea
  • Very heavy periods
  • Bleeding but no ovulation, called anovulatory periods

Other symptoms may include:

  • Infertility
  • Increased hair growth on the face, chest, belly, or upper thighs, called hirsutism
  • Severe, late-onset, or persistent acne that does not respond well to common treatments
  • Insulin sensitivity
  • Obesity, weight gain, or trouble losing weight, especially around the waist
  • Oily skin
  • Patches of thickened, dark, velvety skin, called acanthosis nigricans

For many adolescents, some of these symptoms may be related to puberty. Many women do not consider oily skin, increased hair growth, or acne to be symptoms of a serious health condition, so they may not mention these things to their healthcare providers. As a result, many women are not diagnosed with PCOS until they have trouble getting pregnant or develop menstrual irregularities.

Women with PCOS are at higher risk for the following health conditions, but having PCOS does not mean they will experience all of these issues:

Cardiovascular Disease

Cardiovascular disease, which includes several conditions such as: 

  • Heart disease
  • High blood pressure
  • High blood triglycerides
  • Atherosclerosis: A buildup of plaque in the form of fat, cholesterol, calcium and other substances in your arteries
  • Cardiomyopathy: A disease of the heart muscle

Heart disease is the leading cause of death in the United States. Healthcare providers should screen women with PCOS for cardiovascular disease on a regular basis.

Mental Health Conditions

Women with PCOS are more likely to experience depression, anxiety, and other mental health challenges.

Uterine Conditions

PCOS raises the risk of endometrial hyperplasia. This is when the lining of the uterus becomes too thick. Women with PCOS also may be more likely to have uterine cancer. Irregular periods, or a lack of periods, can cause the endometrium to build up and thicken, which can lead to endometrial cancer.

Insulin Resistance

Many women with PCOS have insulin resistance, which is when the body doesn’t use insulin well. Too much sugar, or glucose, and insulin in the blood can contribute to metabolic syndrome and type 2 diabetes. Patches of thickened, dark, velvety skin, called acanthosis nigricans, are associated with insulin resistance.

Metabolic Syndrome

Many women with PCOS have metabolic syndrome. This is a group of risk factors for heart disease and type 2 diabetes. This is a group of conditions that together increase the risk of heart disease, stroke, type 2 diabetes, or other complications.

Obesity

Most women with PCOS also have obesity. Obesity is a risk factor for many health problems, including diabetes, heart disease, high blood pressure, and sleep apnea.

Obstructive Sleep Apnea

Women with PCOS are at much higher risk for obstructive sleep apnea. This is when breathing stops and restarts during sleep. Sleep apnea increases the risk of high blood pressure, heart attack, and diabetes.

Type 2 Diabetes

Many women with PCOS will have either type 2 or prediabetes before their early 40s. If not managed, diabetes can damage the kidneys and can lead to blindness, nerve damage, and foot problems. Type 2 diabetes also increases the risk for heart disease and high blood pressure.

Cancer

Research shows that the risk of endometrial cancer may be higher for people with PCOS than for people without PCOS.

Pregnancy Complications

Although PCOS is a leading cause of infertility, many women of reproductive age with PCOS can and do get pregnant. Women with PCOS are at higher risk for certain pregnancy complications, including:

  • Miscarriage or early loss of pregnancy; women with PCOS are three times as likely to miscarry in early pregnancy
  • Gestational diabetes
  • Preeclampsia
  • Pregnancy-induced high blood pressure
  • Preterm birth
  • Caesarean delivery or C-section

Infants born to mothers with PCOS are also more likely to require time in the neonatal intensive care unit and have a higher risk of death before, during, or right after birth.

Causes and Risk Factors

Research shows that genetic and environmental factors contribute to the development of PCOS, but its exact cause remains unknown.

Genetics

The symptoms of PCOS tend to run in families. Recent research suggests there are 19 possible changes, or variants, in genes that can increase a person’s risk of developing PCOS. These variants could explain why the features and symptoms of PCOS are so different from one person to the next.

Although PCOS is usually considered a condition related to the ovaries, researchers found these genetic variants in both females and males. Males with these genetic variants experienced cardiac and metabolic symptoms like those experienced by females with PCOS.

Research conducted in animal models also suggests that exposure to increased levels of androgen hormones in the womb may increase the likelihood of PCOS in offspring.

Hormonal Imbalance

Many symptoms of PCOS result from a hormonal imbalance. Women with PCOS have higher levels of androgens and may have lower levels of estrogen. High androgen levels can:

  • Interfere with brain signals that control ovulation, making it occur sporadically or not at all
  • Cause ovarian follicles (small, fluid-filled sacs where eggs grow and mature) to stop developing and clump together
  • Play a role in increased hair growth and acne

Insulin Problems

Many women with PCOS have problems with insulin, a hormone that helps move sugar (glucose) from the bloodstream into cells to use as energy. When cells do not respond normally to insulin, blood sugar levels rise. High insulin levels are linked to acanthosis nigricans, a skin condition that results in thickened, dark, velvety patches of skin.

The body then produces more insulin to move glucose into cells. To balance out high insulin levels, the body makes more androgens, which contribute to PCOS symptoms. This cycle is difficult to break. This is part of why it can be challenging to treat PCOS.

Diagnosis

Because symptoms of PCOS can differ widely, researchers and healthcare providers focus on specific features to diagnose the condition.

Most diagnostic approaches require two of the following three symptoms:

  1. Absence of ovulation or irregular ovulation, resulting in menstrual irregularities such as light periods or skipped periods
  2. High levels of androgens that do not result from other causes or conditions, or signs of high androgens, such as increased body or facial hair
  3. Growths of a specific size in one or both ovaries, often clumps of ovarian follicles that have stopped developing, as detected by ultrasound

Different diagnostic approaches exist:

  • One approach requires only features 1 and 2
  • Another looks for any 2 of the 3 features
  • A third requires feature 1, plus feature 2 or 3

Current diagnostic guidelines apply to adults. There are no diagnostic criteria for PCOS in adolescents. Some adolescents may be considered “at risk” for PPCOS if they have some symptoms. Healthcare providers can re-evaluate their symptoms and health later in life.

Treatment and Management

Treatments for PCOS, its specific symptoms, and its associated health problems vary. They may include medicines, lifestyle changes, and ways to address increased hair growth and acne. The treatment your healthcare provider suggests will depend on your symptoms, overall health, and plans for pregnancy.

Many treatments for PCOS are not approved by the U.S. Food and Drug Administration specifically for treating PCOS, meaning they cannot cure or prevent the condition. However, a healthcare provider may recommend them to treat symptoms such as acne and irregular periods.

Treatments have risks and side effects. Some may be serious. Talk with your healthcare provider about all risks and possible side effects before making decisions about treatments.

Lifestyle Changes

If a person with PCOS carries excess weight or has obesity, losing a small amount of weight and being more physically active can minimize many PCOS symptoms and related health issues, especially cardiovascular risks.

Specifically:

  • Weight loss can restore ovulation and help make menstrual cycles more regular, which can improve chances of pregnancy and overall health.
  • Losing weight can improve both insulin and cholesterol levels.
  • For many women with PCOS, weight loss also reduces symptoms like increased hair growth and acne.
  • Physical activity can help reduce depression associated with PCOS.

Adjusting your diet to reduce foods that can cause or increase inflammation could be beneficial. Talk to your healthcare provider about designing a diet and physical activity plan just for you.

Oral Contraceptives

Also called birth control pills or “the pill,” oral contraceptives containing estrogen and progestin are the primary long-term treatment option for women with intact ovaries who have PCOS who do not wish to become pregnant. In women with PCOS, these hormones:

  • Make menstrual periods more regular
  • Reduce the level of androgens, leading to lower androgen activity
  • Help clear acne and reduce increased hair growth

Birth control pills that contain a low-androgenic progestin are more effective at treating the symptoms of PCOS.

Insulin-Sensitizing Medicines

These medicines make the body more responsive to insulin and keep glucose levels more stable. In women with PCOS, they can help:

  • Clear acne and reduce hair growth
  • Improve weight loss
  • Lower cholesterol levels
  • Make periods more regular
  • Slightly reduce infertility associated with PCOS

After 4–6 months of using these medicines, women with PCOS who have ovaries may start ovulating naturally. Insulin-sensitizing medicines, such as metformin, are not approved by the U.S. Food and Drug Administration to treat PCOS but may help reduce symptoms.

Anti-Androgens

These medicines either prevent the body from making androgens or limit the effects of those hormones. In women with PCOS, anti-androgens can lower androgen levels, reduce hair growth, and clear acne. Because anti-androgens can cause congenital anomalies, they are often taken with oral contraceptives to prevent pregnancy. Anti-androgen medicines are not approved by the U.S. Food and Drug Administration to treat PCOS but may help reduce symptoms.

Treatments for Unwanted Hair Growth

Options for managing unwanted hair include:

  • Eflornithine cream—daily application slows hair growth, especially on the face, by blocking an enzyme hair needs to grow. The hair will grow back when use of the cream stops. Eflornithine is approved by the U.S. Food and Drug Administration to treat unwanted facial hair. Pregnant women should not use this cream because it can harm the fetus.
  • Mechanical methods—shaving, bleaching, plucking, waxing, and using depilatories (creams that dissolve hair) are effective at temporarily removing or hiding unwanted hair. Some of these methods, such as shaving and plucking, are associated with skin irritation and the development of ingrown hairs. Similarly, some depilatories can cause irritation and rashes.
  • Permanent or long-term removal—electrolysis, lasers, and intense pulsed light therapy are options. These treatments may require multiple sessions. Electrolysis uses an electric current applied to each hair follicle to destroy its root. Laser hair removal uses a laser beam to destroy the root of the hair follicle. IPL therapy uses an intense flash of light in a specific wavelength to target the melanin, or color, in hair to destroy the hair follicle.

Treatments for Infertility

Fertility problems related to PCOS are often linked to the absence of ovulation. In most cases, PCOS-related infertility is treatable. Healthcare providers may recommend the following treatments:

  • Clomiphene is the most common treatment for infertility in women with PCOS. The American College of Obstetricians and Gynecologists (ACOG) recommends clomiphene as the primary medicine for women with PCOS-related infertility. It causes eggs to mature and be released. This medicine is approved by the U.S. Food and Drug Administration to treat infertility related to PCOS. Research shows that women who conceive with the aid of clomiphene are slightly more likely to have multiples, most commonly twins.
  • Metformin is an insulin-sensitizing agent and can be used alone or with clomiphene to encourage or regulate ovulation. It is not approved by the U.S. Food and Drug Administration to treat infertility related to PCOS. Evidence shows that metformin, alone and in combination with clomiphene, improves ovulation, but it does not increase the rate of pregnancy.
  • Letrozole is a medicine that slows estrogen production and causes the body to make more follicle-stimulating hormone, a hormone needed for ovulation.
  • Gonadotropins are hormones given as shots to stimulate ovulation. This treatment carries a higher risk of multiple pregnancies than clomiphene.
  • Ovarian drilling surgery is a surgical option considered when lifestyle changes and medicines are unsuccessful. The surgeon uses a needle with electric current to puncture and destroy a small part of the ovary. This may lead to lower androgen levels and improved ovulation. This surgery carries a risk of scarring the ovaries.
  • In vitro fertilization or other types of assisted reproductive technology (ART) may be an option if other treatments are not successful. IVF may offer the best chance of pregnancy for women with PCOS. Different types of ART have their own risks and benefits. You should discuss all the options thoroughly with your healthcare provider before deciding.

Living With PCOS

Living with PCOS can affect many parts of daily life. It is important to work closely with your healthcare provider to manage your specific symptoms and monitor your overall health. Women with PCOS and their healthcare providers may want to monitor for related health issues, such as cardiovascular disease, diabetes, and sleep apnea.

If you have PCOS and get pregnant, work with your healthcare provider to promote a healthy pregnancy and delivery.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on polycystic ovary syndrome.

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Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

NIH supports research on PCOS, including its possible causes, better ways to diagnose the condition, and effective treatments. Current research is exploring:

  • Genetic causes of PCOS
  • Precursors or predictors of PCOS in adolescents
  • Pathophysiological mechanisms of PCOS
  • The effects of nutrition and the gut microbiome on PCOS
  • New treatment strategies

Researchers are also exploring whether women with PCOS have detectable markers of the condition in childhood and the teen years, to better pinpoint diagnosis and improve care.

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.