Endometriosis, a gynecological disorder that affects as many as 1 in 10 women. With symptoms being the most severe during the reproductive years don't necessarily disappear once a woman stops menstruating, according to a Harvard Study.

Endometriosis with symptoms including menstrual cramps, gastrointestinal problems, and pain during sex occurs when tissue similar to the lining of the uterus shows up on the walls of the abdominal cavity and the outer surfaces of the uterus, ovaries, fallopian tubes, bowel, bladder, and nearby organs.

But rather than exiting through the vagina, the way menstrual fluid does, it remains trapped, triggering inflammation and scar tissue.

But even after periods have ceased, the ovaries continue to produce small amounts of the hormone, so endometriosis may continue to cause trouble.

Dr. Martha K. Richardson says, "I think of endometriosis as a chronic disease that often -- but not always -- improves after natural or surgical menopause."

Women with endometriosis also have a higher-than-average risk of autoimmune disorders and related problems, such as chronic fatigue syndrome, hypothyroidism, and fibromyalgia. They're also more likely to develop ovarian cancer.