The primary symptom of endometriosis is pelvic pain, often associated with your menstrual period. Although many women experience cramping during their menstrual period, women with endometriosis typically describe menstrual pain that's far worse than usual. They also tend to report that the pain has increased over time.
Common signs and symptoms of endometriosis may include:
- Painful periods (dysmenorrhea). Pelvic pain and cramping may begin before and extend several days into your period and may include lower back and abdominal pain.
- Pain with intercourse. Pain during or after sex is common with endometriosis.
- Pain with bowel movements or urination. You're most likely to experience these symptoms during your period.
- Excessive bleeding. You may experience occasional heavy periods (menorrhagia) or bleeding between periods (menometrorrhagia).
- Infertility. Endometriosis is first diagnosed in some women who are seeking treatment for infertility.
- Other symptoms. You may also experience fatigue, diarrhea, constipation, bloating or nausea, especially during menstrual periods.
The severity of your pain isn't necessarily a reliable indicator of the extent of the condition. Some women with mild endometriosis have extensive pain, while others with advanced endometriosis may have little pain or even no pain at all.
Endometriosis is sometimes mistaken for other conditions that can cause pelvic pain, such as pelvic inflammatory disease (PID) or ovarian cysts. It may be confused with irritable bowel syndrome (IBS), a condition that causes bouts of diarrhea, constipation and abdominal cramping. IBS can accompany endometriosis, which can complicate the diagnosis.
When to see a doctor
See your doctor if you have signs and symptoms that may indicate endometriosis. The cause of chronic or severe pelvic pain may be difficult to pinpoint. But discovering the problem early may help you avoid unnecessary complications and pain.
Although the exact cause of endometriosis is not certain, several possible explanations include:
- Retrograde menstruation. This is the most likely explanation for endometriosis. In retrograde menstruation, menstrual blood containing endometrial cells flows back through the fallopian tubes and into the pelvic cavity instead of out of the body. These displaced endometrial cells stick to the pelvic walls and surfaces of pelvic organs, where they grow and continue to thicken and bleed over the course of each menstrual cycle.
- Embryonic cell growth. The cells lining the abdominal and pelvic cavities come from embryonic cells. When one or more small areas of the abdominal lining turn into endometrial tissue, endometriosis can develop.
- Surgical scar implantation. After a surgery, such as a hysterectomy or C-section, endometrial cells may attach to a surgical incision.
- Endometrial cells transport. The blood vessels or tissue fluid (lymphatic) system may transport endometrial cells to other parts of the body.
- Immune system disorder. It's possible that a problem with the immune system may make the body unable to recognize and destroy endometrial tissue that's growing outside the uterus.
Several factors place you at greater risk of developing endometriosis, such as:
- Never giving birth
- One or more relatives (mother, aunt or sister) with endometriosis
- Any medical condition that prevents the normal passage of menstrual flow out of the body
- History of pelvic infection
- Uterine abnormalities
Endometriosis usually develops several years after the onset of menstruation (menarche). Signs and symptoms of endometriosis end temporarily with pregnancy and end permanently with menopause, unless you're taking estrogen.
The main complication of endometriosis is impaired fertility. Approximately one-third to one-half of women with endometriosis have difficulty getting pregnant.
For pregnancy to occur, an egg must be released from an ovary, travel through the neighboring fallopian tube, become fertilized by a sperm cell and attach itself to the uterine wall to begin development. Endometriosis may obstruct the tube and keep the egg and sperm from uniting. But the condition also seems to affect fertility in less-direct ways, such as damage to the sperm or egg.
Even so, many women with mild to moderate endometriosis can still conceive and carry a pregnancy to term. Doctors sometimes advise women with endometriosis not to delay having children because the condition may worsen with time.
Ovarian cancer does occur at higher than expected rates in women with endometriosis. But the overall lifetime risk of ovarian cancer is low to begin with. Some studies suggest that endometriosis increases that risk, but it's still relatively low. Although rare, another type of cancer — endometriosis-associated adenocarcinoma — can develop later in life in women who have had endometriosis