How Is Endometriosis Diagnosed?

Endometriosis is usually diagnosed on the basis of a history of pelvic pain, a physical examination, and a laparoscopy. Pelvic pain is symptomatic of many disorders—such as pelvic inflammatory disease (PID), ovarian cysts, and ectopic pregnancy—therefore, it is not definitive.

Laparoscopy is the most important diagnostic tool for endometriosis. Not all women require a laparascopy, however. Patients with mild or moderate symptoms often choose hormonal treatment. If hormones are successful (i.e., reduce pain), laparascopy is not necessary. A laparascopy is necessary if initial hormone treatment does not work or if endometriosis is severe or debilitating.

Imaging tests may be used to locate endometrial lesions. Looking for a biochemical marker that is indicative of endometriosis may also be helpful. The use of biochemical markers may eventually replace the need for laparascopy.

Medical history

About 90 percent of women with pelvic pain have endometriosis. Pelvic pain that is typical of endometriosis includes menstrual cramps, low back pain that worsens during menstruation, and pain in the pelvis that occurs during or after sexual intercourse. Depending on where the implants are located, a woman may feel pain in her rectum and during defecation.

Physical examination

A pelvic examination involves the physician feeling and looking for abnormalities that are associated with endometriosis. Physical findings depend on the severity and location of the condition. There may be palpable nodules or tenderness in the pelvic region, enlarged ovaries, a tipped-back (retrodisplaced or retroflexed) uterus, or lesions on the vagina or on surgical scars.


A laparoscopy is an exploratory procedure that permits the physician to see inside the pelvic region to observe endometrial growths. The procedure involves making a small incision near the navel and inserting a laparascope (long, thin, lighted instrument). Usually, the endometrial implants can easily be seen. Because endometrial implants vary in appearance and can be mistaken for other conditions, the lesions usually must be surgically removed and examined under a microscope to confirm the diagnosis. After laparoscopy, patients can usually resume normal activities in about a day.

Imaging tests

Imaging tests (e.g., pelvic ultrasound, magnetic resonance imaging [MRI scan]) may be used to identify individual endometrial lesions, but they are not used to determine the extent of the condition. The implants are not easily identified using these tests.

Biochemical markers

There are biochemical markers that are associated with the occurrence of endometriosis. For example, many patients with endometriosis have an elevated CA-125 blood level (CA-125 is an antigen), thus CA-125 may be associated with endometriosis. CA-125 is also associated with ovarian cancer. An endometrial protein known as PP14 may also be an indicator of endometriosis.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 31 Oct 2000

Last Modified: 14 Sep 2015