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.
Endometriosis is a common and painful disease that affects about 5.5 million women in North America and is one of the top three causes of infertility in women.
During a normal menstrual cycle, the lining of your uterus -- called the endometrium -- begins to thicken in preparation for becoming pregnant. If you don't become pregnant that month, your body sheds the endometrium during menstruation and the process starts over. In endometriosis, for reasons that doctors don't entirely understand,...
Some women have no symptoms or problems. Others have mild to severe
infertility. There is no way to predict whether
endometriosis will get worse, will improve, or will stay the same until
Between 20% and 40%
of women who are infertile have endometriosis (some have more than one possible
cause of infertility).1 Experts don't fully
understand how endometriosis causes infertility. It could be that:2
Scar tissue (adhesions) may
form at the sites of implants and change the shape or function of the ovaries,
fallopian tubes, or
The endometrial implants may change the
chemical and hormonal makeup in the fluid that surrounds the organs in the
abdominal cavity (peritoneal fluid). This may change the menstrual cycle or prevent a pregnancy.
A common complication of
endometriosis is the development of a cyst on an ovary. This blood-filled
growth is called an
ovarian endometrioma or an endometrial cyst.
Endometriomas can be as small as 1 mm or
more than 8 cm across. The symptoms of an ovarian cyst may be the same as those of endometriosis.