Endometriosis Symptoms

Up to forty percent of patients with endometriosis have no symptoms. Even women with severe endometriosis may be asymptomatic. Conversely, some patients with mild endometriosis may present with debilitating symptoms, particularly pelvic pain.

Causes of Pelvic Pain

Pelvic pain is by far the most common symptom, with around eighty percent of patients with endometriosis symptoms experiencing varying degrees of pelvic pain. Pelvic pain caused by endometriosis may be chronic or related to menstruation.


Some endometriosis symptoms, including pelvic pain, may be caused by unrelated conditions such as:

  • ovarian cysts
  • uterine fibroids
  • urinary tract infection
  • bladder stones
  • kidney stones
  • overactive bladder
  • irritable bowel syndrome
  • inflammatory bowel disease
  • depression.

Other endometriosis symptoms include:

  • infertility
  • changed menstrual pattern
  • heavier, longer and increasingly painful periods
  • premenstrual spotting
  • abdominal pain, sometimes related to the menstrual cycle with severe pain or cramps one week before menstruation
  • pelvic pain accompanied by abdominal bloating
  • pelvic masses with tenderness in the pelvic region, sometimes caused by endometrial cellsin the region of the ovaries, fallopian tubes and supporting structures
  • lower back pain
  • painful intercourse, noticeably worse before or during menstruation
  • painful bowel movements
  • rectal bleeding during menstruation
  • pain while urinating
  • fatigue
  • visible lesions on the vulva, cervix or in the vagina.

Endometriosis and Cancer

Increased levels of CA125 (a protein) in the blood may indicate the presence of endometriosis. Test results should be interpreted with caution, as cancer of the ovaries can also cause elevated levels of CA125. However, increased levels due to endometriosis do not increase the likelihood of developing cancer.

The dark ovarian cysts (also known as “blood cysts” or “chocolate cysts”), associated with endometriosis and infertility causes, are not cancer-related.

Endometriosis and Infertility Causes

Endometriosis is a major cause of infertility; 35 to 50 percent of women who have problems becoming pregnant exhibit some endometriosis symptoms, typically pelvic pain. In more advanced endometriosis stages, adhesions and scarring can cause further distortion of the normal functioning of the uterus, accompanied by severe and/or chronic pelvic pain. The ovaries and fallopian tubes may also become inflamed, further complicating infertility.

Endometriosis may cause infertility in several different ways, including:

  • anatomical distortion
  • hormonal abnormality
  • changes to the immune system
  • interference with sperm function
  • changes in the biochemical environment of the pelvic area
  • adverse effects on embryo implantation.

Studies have shown that surgical removal of ectopic endometrial cell tissue may result in increased fertility, compared with women suffering from infertility related to endometriosis who do not undergo surgery.


U.S. National Library of Medicine