Polycystic Ovary Syndrome (PCOS): Overview

What is polycystic ovary syndrome (PCOS)?

Polycystic ovary syndrome (PCOS) is a health issue that can affect women and teens of the reproductive age. This condition occurs when teens have extra testosterone (a male hormone) in their body. Due to the increased amount of testosterone, the physical symptoms of PCOS start to show. PCOS affects the menstrual cycle, hair growth, skin, weight, and the ability to have children.

What causes polycystic ovary syndrome (PCOS)?

PCOS is thought to be caused by a mixture of genetic factors and weight gain. Many teens who have PCOS are overweight, and more than half have family members with either PCOS or type 2 diabetes.

Weight gain is a cause of PCOS

For overweight teens, decreased physical activity causes weight gain, which increases the amount of insulin in the body. As a result, the increased level of insulin causes more testosterone to be released from the ovaries. The extra testosterone causes the physical symptoms of PCOS, like hair growth.

Excess testosterone is a cause of PCOS

In women who are not overweight, it is thought that the ovaries make too much testosterone.

In all women with PCOS, the ovaries don’t work very well. In a healthy female, once a month the ovaries make a follicle (where an egg grows). As the follicle grows, it makes hormones and then it releases an egg. This is commonly referred to as “ovulation.”

However, the ovary in a woman who has PCOS makes many small follicles instead of one big one. The follicle looks like a cyst on ultrasound and gives us the name “polycystic ovaries.” Although the follicles are harmless, hormone levels become out of balance and ovulation doesn’t happen every month the way it is supposed to due to the increased amount of follicles. As a result, periods become irregular or stop altogether. 

Who gets polycystic ovary syndrome (PCOS)?

Genetics do play a role in causing PCOS, but the condition is also caused by weight gain and other unknown factors.

Is this a common condition?

Yes – about 5-10% of all women have PCOS.

Helpful resources for PCOS:

More information about polycystic ovary syndrome (PCOS) is available from the following resources:

The multidisciplinary PCOS Clinic at Children’s Hospital Colorado

U.S. Department of Health and Human Services

Download this information on polycystic ovary syndrome (PCOS) en Español (pdf).

For Healthcare Professionals: Frequently Asked Questions

Find out more about the Adolescent Gynecology Department at Children’s Colorado.