Polycystic ovarian syndrome is also known as Stein-Leventhal Syndrome. The disorder affects 5 to 10 percent of adolescents and women of reproductive age and is the most common cause of irregular menstruation. It is characterized by an excess of male hormones that disrupt the normal ovulation. (In normal ovulation, a single egg develops in the ovary and is released each month)
Many girls with PCOS also have a metabolic abnormality known as insulin resistance, which causes their bodies to produce an excess of insulin. This is seen more often in overweight girls but lean girls may also be affected. Excess insulin in fact, is often the culprit behind the excess male hormones. Too much insulin may cause the ovary to produce too much androgen, a male hormone.

Common symptoms of PCOS are:

• irregular periods or absence of periods
• irregular ovulation or no ovulation
• numerous cysts in the ovaries in many, but not all, cases
  (Cysts in a polycystic ovary are follicles that have matured, but due to abnormal hormone levels, were never released)
• excess hair on the face and body (hirsutism)
• oily skin, acne
• being overweight, rapid weight gain; difficulty in losing weight
  PCOS affects each individual in a different way. Some may only have a couple of mild symptoms, whilst others may exhibit a wider range of symptoms more severely.
  The condition has long-term health implications as girls with PCOS may have an increased risk of infertility, diabetes, high blood pressure and heart disease later in life.