Endometriosis is usually a long-lasting (chronic)
disease. When you have
endometriosis, the type of tissue that lines your uterus is
also growing outside your uterus. The clumps of tissue (called implants) may have grown on your ovaries or
fallopian tubes, the outer wall of the
uterus, the intestines, or other organs in the belly. In rare cases they
spread to areas beyond the belly.
With each menstrual cycle, the implants go through the
same growing, breaking down, and bleeding that the uterine lining (endometrium)
goes through. This is why endometriosis pain may
start as mild discomfort a few days before the menstrual period and then usually
is gone by the time the period ends. But if an implant grows in a sensitive
area, it can cause constant pain or pain during certain activities, such as
sex, exercise, or bowel movements.