Endometriosis (cont.)
What causes endometriosis?
The cause of endometriosis is unknown. One theory is that
the endometrial tissue is deposited in unusual locations by the backing up of
menstrual flow
into the Fallopian tubes and the pelvic and abdominal cavity during menstruation
(termed retrograde menstruation). The cause of retrograde menstruation is not
clearly understood. But retrograde menstruation cannot be the sole cause of
endometriosis. Many
women have retrograde menstruation in varying degrees, yet not all of them
develop endometriosis.
Another possibility is that areas lining the pelvic organs possess primitive
cells that are able to grow into other forms of tissue, such as endometrial
cells. (This process is termed coelomic metaplasia.)
It is also likely that direct transfer of endometrial tissues during surgery
may be responsible for the endometriosis implants sometimes seen in surgical
scars (for example, episiotomy or
Cesarean section scars). Transfer of
endometrial cells via the bloodstream or lymphatic system is the most likely
explanation for the rare cases of endometriosis that develop in the brain and
other organs distant from the pelvis.
Finally, some studies have shown alternations in the immune response in women
with endometriosis, which may affect the body's natural ability to recognize and
destroy any misdirected growth of endometrial tissue.
What are endometriosis symptoms?
Most women who have endometriosis, in fact, do not have
symptoms. Of those who do experience symptoms, the common symptoms are pain
(usually pelvic) and infertility. Pelvic pain usually occurs during or just
before menstruation and lessens after menstruation. Some women experience pain
or cramping with intercourse, bowel movements and/or urination. Even pelvic
examination by a doctor can be painful. The pain intensity can change from month
to month, and vary greatly among women. Some women experience progressive
worsening of symptoms, while others can have resolution of pain without treatment.
Pelvic pain in women with endometriosis depends partly on where the implants
of endometriosis are located.
- Deeper implants and implants in areas with many
pain-sensing nerves may be more likely to produce pain.
- The implants may also produce
substances that circulate in the bloodstream and cause pain.
- Lastly, pain can
result when endometriosis implants form scars. There is no relationship between
severity of pain and how widespread the endometriosis is (the "stage" of
endometriosis).
Endometriosis can be one of the reasons for infertility in otherwise healthy
couples. When laparoscopic examinations are performed for infertility
evaluations, endometrial implants can be found in some of these patients, many
of whom may not have painful symptoms of endometriosis. The reasons for a
decrease in fertility are not completely understood, but might be due to both
anatomic and hormonal factors. The presence of endometriosis may involve masses
of tissue or scarring (adhesions) within the pelvis that may distort normal
anatomical structures, such as Fallopian tubes, which transport the eggs from
the ovaries. Alternatively, endometriosis may affect fertility through the
production of hormones and other substances that have a negative effect on
ovulation, fertilization of the egg, and/or
implantation of the embryo.
Other symptoms related to endometriosis include:
Rare symptoms of
endometriosis include chest pain
or coughing blood due to endometriosis in the lungs and headache and/or
seizures due to endometriosis in the brain.
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