Irregular menstrual periods can be one of the first symptoms of polycystic ovarian syndrome, or PCOS. It can also spur development of male characteristics such as excess hair growth, acne, or male-pattern baldness.
PCOS occurs when excess androgen (a male hormone, such as testosterone) is produced by the ovaries. This, in turn, can keep the ovaries from releasing an egg, resulting in skipped or absent periods. PCOS can lead to enlarged ovaries, ovarian cysts, and infertility. Excess insulin levels in the body may be at the root of increased androgen production in women.
Treatment of PCOS tends to focus on addressing symptoms, such as hormone therapy to normalize menstrual periods, and other medications to address individual issues such as insulin resistance, excess hair growth, etc.