Endometriosis is a disease affecting some women in their reproductive years. Endometrial tissue is the interior lining of the uterus that normally is shed each month during menstruation. However, when a woman is diagnosed with endometriosis it means that endometrial tissue is also forming outside of the uterus.

The tissue develops into small growths, or tumor-like structures that are almost always benign. This endometrial tissue is most often located in the pelvic region, but in rare cases is found in places such as the lungs, arms, or legs.

Because these growths are pieces of uterine lining, they do what uterine lining normally does every month; the tissue grows and tries to be shed. It's as if the tissue doesn't know it's not in the uterus. The big problem is that if this tissue is located outside of the uterus there is no vagina for it to pass through after it is shed. The result can be internal bleeding, degeneration of the blood and tissue shed from the growths, inflammation, and the formation of scar tissue. Sufferers of this disease commonly experience pain before and during menstruation, and during or after intercourse. There is also a risk of infertility with endometriosis.

There is no absolute cure for the disease, but mild symptoms can often be alleviated with regular painkillers. For more severe symptoms your doctor might recommend treatment, such as a hysterectomy or other surgery.

Until recently, endometriosis went undiagnosed. Interestingly, what is now recognized to be a serious condition was once coined "husbanditis" because it was believed that the pain women reported was simply an excuse to get out of what were called "marital duties."