University of Colorado Anschutz Medical Campus

About Polycystic Ovary Syndrome (PCOS)

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 can cause 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

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

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 follicle. The follicles look like cysts on ultrasound, thus giving 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 PCOS?

Often, PCOS is diagnosed in female adolescents. PCOS can be difficult to diagnose during this stage of life, due to the overlap of normal pubertal developmental symptoms and PCOS symptoms. Genetic factors play a role in causing PCOS, but this condition is also caused by weight gain and other currently unknown factors. This condition is common, 5-10% of all women have PCOS.