How is endometriosis diagnosed?

How Is Endometriosis Diagnosed?

Endometriosis occurs when tissue similar to the lining of the uterus grows outside the uterine cavity, most often on the ovaries, fallopian tubes and pelvic lining. It affects up to 10% of women of reproductive age and can cause pain, heavy periods and fertility problems. Early and accurate diagnosis helps guide treatment, relieve symptoms and preserve fertility. Here's how clinicians arrive at a diagnosis.

Initial Evaluation: Symptoms and History
A careful medical history and symptom review guide further testing.

Common symptoms

• Painful periods (dysmenorrhea)
• Chronic pelvic pain
• Pain during or after intercourse (dyspareunia)
• Painful bowel movements or urination during menstruation
• Heavy or irregular bleeding
• Infertility

Because these symptoms overlap with other conditions (e.g., ovarian cysts, irritable bowel syndrome), your doctor will ask about timing, severity and impact on daily life. Before scheduling your appointment, you can use Ubie's free AI-powered endometriosis symptom checker to quickly assess your symptoms and help prepare a more detailed discussion with your healthcare provider.

Physical Examination
A pelvic exam may detect:

• Tenderness behind the uterus
• Nodules or fixed "barrier" feeling (from deep lesions)
• Enlarged ovaries or endometriomas (chocolate cysts)

In many cases, the exam is normal or non-specific—especially if lesions are small or out of reach. A normal exam does not rule out endometriosis.

Imaging Studies
Non-invasive imaging helps identify endometriomas and some deep-infiltrating lesions, but small implants on peritoneal surfaces often remain undetected.

1. Transvaginal Ultrasound (TVUS)

   • First-line imaging test.
   • High specificity (up to 94%) for endometriomas (ovarian cysts filled with old blood).
   • Can detect deep infiltrating endometriosis (DIE) affecting the rectovaginal septum or bladder.
   • Limited for superficial peritoneal implants.

2. Magnetic Resonance Imaging (MRI)

   • Offers detailed soft-tissue contrast.
   • Useful when TVUS is inconclusive or for complex cases (e.g., suspected disease involving bowel or urinary tract).
   • According to Nisenblat et al. (2016), MRI has good accuracy for detecting endometriomas and DIE, though its availability and cost may limit routine use.

3. Other Modalities

   • Sonovaginography or rectal water-contrast TVUS: enhances detection of bowel lesions.
   • Computed Tomography (CT): rarely used for primary diagnosis but may help rule out other pelvic or abdominal causes of pain.

Blood Tests and Biomarkers
No blood test can definitively diagnose endometriosis. Elevated CA-125 levels occur in about 50% of women with endometriosis, especially those with advanced disease, but it lacks sensitivity and specificity:

• Normal CA-125 does not exclude endometriosis.
• High CA-125 may reflect other conditions (e.g., ovarian cancer, fibroids, pelvic inflammatory disease).
• Research continues into novel biomarkers, but none are yet reliable for routine clinical use.

Diagnostic Laparoscopy: The Gold Standard
When clinical evaluation and imaging suggest endometriosis but cannot confirm it, laparoscopy remains the definitive diagnostic tool.

1. Procedure

   • A minimally invasive surgery under general anesthesia.
   • Small incisions (5–10 mm) in the abdomen allow insertion of a camera (laparoscope) and instruments.

2. Visual Confirmation

   • Surgeons look for endometrial-like implants on ovaries, peritoneum, bladder, intestine or elsewhere.
   • Lesions vary in color—from red/purple "powder-burn" spots to white, clear or black "chocolate" cysts.

3. Biopsy and Histology

   • Suspect lesions are biopsied or excised.
   • Pathology confirms endometrial glands and stroma outside the uterus.

4. Staging and Treatment

   • The revised American Society for Reproductive Medicine (rASRM) scoring system stages endometriosis from I (minimal) to IV (severe).
   • Many surgeons combine diagnosis with surgical treatment—removing or ablating lesions and adhesions during the same procedure.

Risks and Considerations

• As with any surgery, laparoscopy carries small risks of bleeding, infection or injury to organs.
• Recovery is usually quick—most return to normal activities within a week.
• Discuss benefits and risks with your gynecologist.

When to Refer and Next Steps
You may be referred to a specialist if you have:

• Persistent pelvic pain unresponsive to over-the-counter pain relievers
• Large endometriomas (>3 cm) on imaging
• Suspected deep infiltrating endometriosis involving bowel or bladder
• Difficulty conceiving for 6–12 months

Early referral and intervention can improve pain control and fertility outcomes.

Putting It All Together
Diagnosing endometriosis often requires combining:

• A thorough clinical history and pelvic exam
• Targeted imaging (TVUS and/or MRI)
• Laparoscopic confirmation with histology when necessary

No single test rules in or out endometriosis, so personalized assessment is key. Imaging may give strong clues, especially for ovarian and deep lesions, but small peritoneal implants may only be found during surgery.

Talking With Your Doctor
If you suspect endometriosis—whether due to painful periods, chronic pelvic pain or fertility concerns—make an appointment with your healthcare provider. Bring a record of your symptoms, pain diary or menstrual calendar to help guide the discussion. Always:

• Be honest about symptom severity and impact on daily life.
• Ask whether imaging tests or referral to a gynecologist specializing in endometriosis is appropriate.
• Discuss surgical versus medical management options, including hormonal therapies and pain relief strategies.

If you experience any symptoms that could be life-threatening or severe—such as sudden, intense abdominal pain, heavy bleeding with dizziness or fainting—speak to a doctor or seek emergency care right away.

In Summary
Endometriosis diagnosis is a step-wise process that balances non-invasive testing with definitive surgical confirmation. Early recognition and a tailored plan can relieve symptoms, protect fertility and improve quality of life. If you have concerns, don't hesitate to discuss them with your healthcare provider.