Polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common hormonal disorder in women of reproductive age. The name comes from the observation of small follicles (or "cysts") that sometimes appear on the ovaries. However, not everyone with PCOS has these follicles, and they are not the cause of the condition.

PCOS is diagnosed when a person has at least two of the following three features: irregular menstrual periods, high testosterone or related symptoms (like excess facial hair), or polycystic ovaries found on an ultrasound. A blood test for high levels of anti-Müllerian hormone can replace the ultrasound in the diagnosis. Other symptoms associated with PCOS are heavy periods, acne, difficulty getting pregnant, and patches of darker skin.

The exact cause of PCOS remains uncertain. There is a clear genetic component, but environmental factors are also thought to contribute. PCOS occurs in between 5% and 18% of women. The disorder is linked to insulin resistance, which is made worse by obesity. Insulin resistance and related excess insulin levels increase the risk of complications such as type 2 diabetes and liver disease. Women with PCOS also have higher risk of endometrial cancer.

Management focuses on relieving symptoms and reducing long-term risks. A healthy lifestyle and weight control are recommended for general management. In addition, hormonal contraception can help to regulate menstrual cycles, to reduce acne and excess hair growth. Metformin, a common anti-diabetes drug, increases insulin sensitivity. For fertility, ovulation can be induced with letrozole, among other methods. In addition, women can be monitored for cardiometabolic risks, and during pregnancy.

PCOS has a wide variety of signs and symptoms. They include issues around ovulation (such as irregular periods), issues related to excess levels of androgens (hormones that trigger male characteristics, such as facial hair growth), and metabolic issues (such as weight gain). Symptoms usually start in puberty, but may be masked if oral contraceptives are started early.

Common signs and symptoms of PCOS are:

The ovaries might be larger than normal, with many small fluid-filled sacs that surround eggs ("cysts"). Testosterone levels are usually elevated: one meta-analysis showed testosterone levels to be 1.5 times higher in women with PCOS compared to women without PCOS.

Women with PCOS have an increased risk of a range of metabolic, cardiovascular, reproductive and mental health conditions. The likelihood of developing metabolic disorders is about three to seven times higher than in women without PCOS. Insulin resistance is common, even in lean women with PCOS. Type 2 diabetes is more likely in overweight or obese women with PCOS, compared to women without PCOS and the same BMI. In contrast, lean women with PCOS do not appear to be at higher risks of developing diabetes. Other metabolic and cardiovascular complications commonly associated with PCOS include: