Patient Guide

Polycystic Ovary Syndrome

  • Editors
  • Kathleen M. Hoeger, MD, MPH, University of Rochester Medical Center

    Richard S. Legro, MD, Penn State University College of Medicine

    Corrine K. Welt, MD, Massachusetts General Hospital

Polycystic ovary syndrome (PCOS) is a common hormonal disorder among girls and women during their reproductive years. Normally, women make small amounts of “male” hormones (called androgens), such as testosterone, but women with PCOS produce slightly higher amounts. This hormone imbalance causes an assortment of health problems, such as irregular menstrual periods, too much hair on the body and face (hirsutism), and a very large number of follicles (small fluid-filled sacs where eggs develop) on the ovaries. These many follicles look like cysts, which is where the term “polycystic” comes from.

This guide for patients comes from The Endocrine Society’s 2013 practice guidelines for physicians about the detection and treatment of PCOS.

Who gets PCOS?

Women and girls who are obese are more likely to have PCOS. It also seems to run in families.

Most often, PCOS symptoms first occur around the start of menstruation, but some women do not get symptoms until their early or mid-20s. Symptoms like excess facial hair and male-pattern baldness can continue even after a woman goes through menopause.

What causes PCOS?

The cause of PCOS remains unknown. There may be more than one cause.

The main problem in this condition is a hormone imbalance. There also is a link between PCOS, obesity, and resistance to insulin, the hormone that carries sugar from the blood into our cells. Many women with PCOS have too much insulin in their bodies because the insulin does not work as well as it should.

What are the signs and symptoms of PCOS?

Not all women with PCOS have all these problems. Each person may have a different mix of these features. Also, other conditions may cause some of these health concerns. For these reasons, PCOS can be hard to diagnose.

Which conditions mimic PCOS?

Before doctors diagnose PCOS, they must first rule out or exclude other conditions with similar symptoms. This is why they call PCOS “a diagnosis of exclusion.”

Some Conditions That Mimic Polycystic Ovary Syndrome (PCOS)
Condition What it is Features similar to PCOS
Thyroid disease Overactive or underactive thyroid gland Irregular menstrual cycle
Prolactin excess The body makes too much of the hormone prolactin Male-type hair growth in women Irregular periods or lack of periods
Cushing syndrome The body makes excess cortisol hormone Weight gain
Too much hair in women
Abnormal menstrual periods
Congenital adrenal hyperplasia Inherited disorder that causes the body to make too little cortisol and too much male hormone Acne that is severe and early (before the teen years)
Infertility or decreased fertility
Facial hair in women and teen girls
Infrequent or absent menstrual periods

How does a doctor diagnose PCOS?

Experts suggest that a diagnosis of PCOS requires the following.

Your doctor will take your medical history, asking about your health and menstrual cycle. A physical exam should include measuring your height, weight, and waistline, and looking for skin and hair problems.

No single test detects PCOS. Sometimes a blood test is needed to measure your hormone levels. To check for a large number of follicles, your doctor may order an ultrasound (usually done through the vagina), which uses sound waves to take pictures of the ovaries. Most teens will not need an ultrasound because it is common to have many follicles at that age.

What tests do you need after diagnosis?

Women with PCOS may need tests to screen for health problems that occur more often in PCOS. These conditions can be serious and include

What is the treatment for PCOS?

Some medications can relieve symptoms of PCOS, and others rebalance your hormones.

The first treatment for most women and teens with PCOS is birth control pills or a contraceptive skin patch or vaginal ring. These medications contain female hormones that help protect the uterus and prevent unpredictable bleeding. They also lower androgen levels, reducing excess hair growth and improving acne. Birth control pills also prevent your uterine lining from thickening, thus lowering the risk of uterine cancer.

Ask your doctor if this treatment option is right for you. Some women should not take the pill due to specific risk factors.

Other treatment options for PCOS symptoms and complications are

More treatments are available to reduce unwanted hair growth, acne, and (to a lesser degree) scalp hair loss. Find more information about these treatments in the Hormone Health Network’s fact sheet on PCOS.

There is no cure for PCOS. But with proper treatment and lifestyle changes, you can improve most of your symptoms and reduce your chance of developing health problems related to PCOS.

Note to health care professionals: This patient guide is based on, and is intended to be used in conjunction with, The Endocrine Society’s clinical practice guidelines (available at