Polycystic ovary syndrome is a disorder involving infrequent or prolonged menstrual periods or excess male hormone (androgen) levels. The ovaries develop numerous small cysts and may fail to release eggs.
Polycystic ovary syndrome (PCOS) is the most common hormonal disorder among women of reproductive age. The name of the condition comes from the appearance of the ovaries in most, but not all, women with the disorder — enlarged and containing numerous small cysts located along the outer edge of each ovary (polycystic appearance).
Infrequent or prolonged menstrual periods, excess hair growth, acne and obesity can all occur in women with polycystic ovary syndrome. Menstrual abnormality may signal the condition in adolescence, or PCOS may become apparent later following weight gain or difficulty becoming pregnant.
The exact cause of polycystic ovary syndrome is unknown. Women with polycystic ovary syndrome may have trouble becoming pregnant due to infrequent or lack of ovulation. Early diagnosis and treatment of polycystic ovary syndrome can help reduce the risk of long-term complications, such as type 2 diabetes, heart disease and stroke.
Polycystic ovary syndrome signs and symptoms often begin soon after you first begin having periods (menarche). In some cases, PCOS develops later on during your reproductive years, for instance, in response to substantial weight gain.
Signs and symptoms vary from person to person, in both type and severity. To be diagnosed with the condition, your doctor looks for at least two of the following:
Menstrual abnormality. This is the most common characteristic. Examples of menstrual abnormality include menstrual intervals longer than 35 days; fewer than eight menstrual cycles a year; failure to menstruate for four months or longer; and prolonged periods that may be scant or heavy.
Excess androgen. Elevated levels of male hormones (androgens) may result in physical signs, such as excess facial and body hair (hirsutism); adult acne or severe adolescent acne; and male-pattern baldness (androgenic alopecia). However, the physical signs of androgen excess vary with ethnicity, so depending on your ethnic background you may or may not show signs of excess androgen. For instance, women of Northern European or Asian descent may not be affected.
Polycystic ovaries. Enlarged ovaries containing numerous small cysts can be detected by ultrasound. Despite the condition’s name, polycystic ovaries alone do not confirm the diagnosis. To be diagnosed with PCOS, you must also have abnormal menstrual cycles or signs of androgen excess. Some women with polycystic ovaries may not have PCOS, while a few women with the condition have ovaries that appear normal.
Other conditions associated with PCOS
Infertility. Women with polycystic ovary syndrome may have trouble becoming pregnant because they experience infrequent ovulation or a lack of ovulation. PCOS is the most common cause of female infertility.
Obesity. About half the women with polycystic ovary syndrome are obese. Compared with women of a similar age who don’t have polycystic ovary syndrome, women with PCOS are more likely to be overweight or obese.
Prediabetes or type 2 diabetes. Many women with polycystic ovary syndrome are insulin resistant, which impairs the body’s ability to use insulin effectively to regulate blood sugar. This can result in high blood sugar and type 2 diabetes. Prediabetes is also called impaired glucose tolerance.
Acanthosis nigricans. This is the medical term for darkened, velvety skin on the nape of your neck, armpits, inner thighs, vulva or under your breasts. This skin condition is a sign of insulin resistance.