What is polycystic ovary syndrome (PCOS)?
Polycystic ovary syndrome (also called PCOS or Stein Leventhal syndrome) is the most common hormonal and reproductive problem affecting women of childbearing age. It's estimated that about 8 to 15 percent of women experience this disorder.
According to the American Society for Reproductive Medicine, PCOS is defined by the presence of any two of the following characteristics:
Lack of ovulation for an extended period of time
High levels of androgens (male hormones)
Many small cysts (fluid-filled sacs) on the ovaries
What causes PCOS?
The exact cause of PCOS is unclear. It's common for sisters or a mother and daughter to have PCOS, but a definite genetic link hasn't been found.
PCOS results from a combination of several related factors. Many women with PCOS have insulin resistance, in which the body can't use insulin efficiently. This leads to high circulating blood levels of insulin, called hyperinsulinemia. It's believed that hyperinsulinemia is related to increased androgen levels, as well as obesity and type 2 diabetes. In turn, obesity can increase insulin levels, causing worsening of PCOS.
How does PCOS affect ovulation?
Ovulation is a process in which a mature egg cell (also called an ovum), ready for fertilization by a sperm cell, is released from one of the ovaries (two female reproductive organs located in the pelvis). If the egg doesn't become fertilized as it travels down the fallopian tube on its way to the uterus, the endometrium (lining of the uterus) is shed and passes through the vagina (the passageway through which fluid passes out of the body during menstrual periods; also called the birth canal), in a process called menstruation.
With an ovulatory problem, the woman's reproductive system doesn't produce the proper amounts of hormones necessary to develop, mature, and release a healthy egg.
When the ovaries don't produce the hormones needed for ovulation and proper function of the menstrual cycle, the ovaries become enlarged and develop many small cysts which produce androgens.
Increased levels of androgens can also interfere with ovulation and normal menstrual cycles. Some women with polycystic ovaries have normal menstrual cycles.
What are the symptoms of PCOS?
The signs and symptoms of PCOS are related to hormonal imbalance, lack of ovulation, and insulin resistance and may include:
Irregular, infrequent, or absent menstrual periods
Hirsutism (excessive growth of body and facial hair, including the chest, stomach, and back)
Acne or oily skin
Enlarged and/or polycystic ovaries
Infertility (the inability to produce children)
Overweight or obesity, especially around the waist (central obesity) and abdomen
Male-pattern baldness or thinning hair
Skin tags (small pieces of skin on the neck or armpits)
Acanthosis nigricans (darkened skin areas on the back of the neck, in the armpits, and under the breasts)
In addition, women with PCOS may be at increased risk for developing certain health problems. These may include:
Metabolic syndrome, a condition with several components, including:
Type 2 diabetes or insulin resistance
Elevated cholesterol levels
High blood pressure
Excess body weight, especially around the waist and abdomen
Elevated levels of C-reactive protein (a marker of inflammation)
Elevated blood clotting factors
Heavy or irregular bleeding and endometrial cancer. Lack of ovulation for an extended period of time may cause excessive thickening of the endometrium (the lining of the uterus).
The symptoms of PCOS may resemble other conditions or medical problems. Always consult your physician for a diagnosis.
How is PCOS diagnosed?
In addition to a complete medical history and physical examination, diagnostic procedures for PCOS may include:
Pelvic examination. This involves a physical examination of both the external and internal female reproductive organs.
Ultrasound (also called sonography). Ultrasound is a diagnostic imaging technique which uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels. Ultrasound can determine if a woman's ovaries are enlarged or if cysts are present and evaluate the thickness of the endometrium. A vaginal ultrasound, in which an ultrasound transducer is inserted into the vagina, is sometimes used to view the endometrium.
Blood tests. These tests are used to detect increased levels of androgens and other hormones.