How Uterine Fibroids Are Diagnosed (Tests & Procedures Explained)

1) Clinical history (symptom assessment)

Diagnosis begins with your bleeding and pressure pattern:

• heavy bleeding (flooding, clots, >7 days)
• intermenstrual spotting (sometimes)
• pelvic heaviness/pressure
• urinary frequency or constipation
• fatigue, breathlessness (suggesting anemia)

This step decides whether you need only ultrasound or additional cavity/mapping tests.

2) Pelvic examination (clinical suspicion)

i. Abdominal examination

Large fibroids may be felt as a firm lower abdominal mass.

ii. Bimanual pelvic examination

The uterus may feel:

• enlarged
• irregular/bosselated
• firm

A pelvic exam raises suspicion, but imaging confirms and maps fibroids.

3) Ultrasound (first-line diagnostic test)

i. Transvaginal ultrasound (TVS)

Most commonly used first. It helps identify:

• presence of fibroids
• size and approximate location
• endometrial thickness
• ovaries and associated adnexal findings

ii. Transabdominal ultrasound (TAS)

Often added when:

• uterus is large
• fibroids extend high into the abdomen
• TVS is limited for full mapping

For many women, ultrasound is enough to diagnose fibroids.

4) Saline Infusion Sonography (SIS) / Sonohysterography (for cavity mapping)

In SIS, sterile saline is introduced into the uterine cavity during ultrasound.

Best used when:

• heavy bleeding suggests submucosal fibroid
• infertility evaluation needs cavity clarity
• ultrasound cannot confidently assess cavity distortion

SIS shows whether fibroids are projecting into the cavity and how much they distort it.

5) Hysteroscopy (direct visual test for intracavitary involvement)

A thin camera is passed through the cervix to see the uterine cavity directly.

Used when:

• imaging suggests a submucosal/intracavitary lesion
• persistent heavy bleeding with unclear cavity findings
• fertility work-up requires definitive cavity assessment

Hysteroscopy confirms:

• exact intracavitary location
• number of lesions in cavity
• degree of cavity distortion

6) MRI pelvis (best test for detailed fibroid mapping)

MRI is not needed for every patient, but it is the most accurate for:

• multiple fibroids
• very bulky uterus where ultrasound mapping is limited
• suspected coexisting adenomyosis
• surgical planning requiring exact planes

MRI provides clear mapping of:

• fibroid type (submucosal/intramural/subserosal)
• relationship to endometrium and serosa
• degeneration patterns
• extension into cervix/broad ligament (if any)

7) Blood tests (supportive tests to assess impact)

Blood tests don’t diagnose fibroids, but they measure consequences and guide safety:

• CBC (Hemogram) – anemia severity
• Serum ferritin – iron stores
• TSH – if thyroid-related bleeding is suspected

8) Endometrial biopsy (only when indicated)

Fibroids themselves don’t require biopsy. Endometrial sampling is done when:

• age ≥45 with abnormal bleeding
• persistent/irregular bleeding not responding to treatment
• risk factors for endometrial hyperplasia
• suspicious endometrial thickness/pattern on ultrasound

This ensures heavy bleeding is not wrongly attributed only to fibroids.

Practical diagnostic pathway (simple and clinically accurate)

• Most patients: History + exam → TVS/TAS ultrasound
• If bleeding suggests cavity involvement: SIS ± hysteroscopy
• If complex/multiple/very large fibroids or planning surgery: MRI pelvis
• If heavy bleeding with risk factors: supportive blood tests ± endometrial biopsy (when indicated)