Types

Polycystic Ovary Syndrome

Choose a preferred language

Polycystic ovary syndrome (PCOS) causes harmless, small cysts in the ovaries and other symptoms. PCOS is caused by certain hormones being out of balance. The word syndrome means a group of symptoms. Women with PCOS may have no periods, irregular periods, or very long or heavy periods.


Your ovaries

Women store their eggs in their ovaries. Each egg is in a capsule called a follicle. Normally during the reproductive years, one follicle grows to make a mature egg each month. This egg is released during ovulation and the follicle dissolves.

Front view of female reproductive tract with insets showing normal ovary and polycystic ovary.


Hormones out of balance

With PCOS, the hormones that control ovulation are out of balance. These include estrogen, progesterone, and androgen. As a result, ovulation may not occur. Instead, the follicle stays enlarged. This is a fluid-filled sac called a cyst. Over time, the ovaries fill with many small cysts. This is why they are called poly or many cystic ovaries. In some women, the ovaries also make too much androgen.


Symptoms of PCOS

Women with PCOS may also have one or more of these symptoms:

  • Acne

  • Hair growth on the face and other parts of the body

  • Patches of thick, velvety, dark skin (acanthosis nigricans), often on the neck or groin area

  • Trouble getting pregnant (fertility problems)

  • Weight gain, often around the waist 

Women with PCOS are also at greater risk of having cancer of the uterine lining, diabetes, and heart disease.

Featured in

Online Medical Reviewer: Donna Freeborn PhD CNM FNP

Online Medical Reviewer: Heather M Trevino BSN RNC

Online Medical Reviewer: Howard Goodman MD

Date Last Reviewed: 05/01/2025

© 2000-2026 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
user headset icon

Need Help? We're Here for You

Our Member and Recipient Services Team is here to help you understand your benefits, find care, or resolve concerns.

800-510-9132
quit smoking icon

Call NC Quitline

Need support to quit smoking, vaping, or to quit other nicotine products? You can receive support including medicines free of charge:

800-784-8669
car and bus icon

Schedule Transportation

Need transportation to a doctor's office, pharmacy, or other covered healthcare service? Contact us to arrange your ride.

800-510-9132
Stethoscope icon

Provider Directory

Need to find a provider like a Primary Care Physician, Specialist, OB/GYN, or a Psychiatrist? 

Provider Directory
Related Articles
Read article
Urology
Urethral Stricture

Narrowing or blockage of the urethra is known as a urethral stricture. This is more common in men than in women.

Read article
OB/GYN
Vulvodynia

Pain in a woman’s vulva is called vulvodynia. Some women feel pain in a specific spot. Others may feel pain in different areas or over the whole area.

Read article
OB/GYN
What Are Fibroids?

Fibroids are growths that usually form in the wall of your uterus. Fibroids are the most common tumor in women. They are almost always noncancerous (benign) and harmless. .

Read article
OB/GYN
Ovarian Cyst

An ovarian cyst is a fluid-filled sac that forms on or inside an ovary. Read on to learn about the causes and types of ovarian cysts, risk factors, symptoms, diagnosis, and treatment.