Endometriosis is a condition in
which the type of tissue that forms the lining of the
uterus (the endometrium) is found outside the uterus.
Endometriosis occurs in about one in ten women of
reproductive age. It is most often diagnosed in women in
their 30s and 40s.
Endometriosis implants respond to changes in estrogen, a
female hormone. The implants may grow and bleed like the
uterine lining does during the menstrual cycle.
Surrounding tissue can become irritated, inflamed and
swollen. The breakdown and bleeding of this tissue each
month also can cause scar tissue, called adhesions, to
form. Sometimes adhesions can cause organs to stick
together. The bleeding, inflammation and scarring can
cause pain, especially before and during menstruation.
Almost 40 percent of women with infertility have
endometriosis. Inflammation from endometriosis may
damage the sperm or egg or interfere with their movement
through the fallopian tubes and uterus. In severe cases
of endometriosis, the fallopian tubes may be blocked by
adhesions or scar tissue.