Your ultrasound report lists fibroid sizes in centimetres or millimetres. But what do those numbers actually mean for how you feel?
Size Is Not the Whole Story
Location matters as much as size. A 1.5cm submucosal fibroid inside the uterine cavity can cause significantly heavier bleeding and more fertility disruption than a 5cm subserosal fibroid on the outer wall. Always know both the size AND the type/location of your fibroids.
General Size Guide
Under 3cm (small): Often asymptomatic. May cause no symptoms unless submucosal. 3–5cm (medium): Increasingly likely to cause symptoms, particularly intramural fibroids of this size. 5–10cm (large): Often symptomatic — pelvic pressure, heavy bleeding, urinary frequency. Over 10cm (very large): Can cause significant distension, pressure, and urinary symptoms. Uterine size is sometimes compared to pregnancy stage at this level.
Rate of Growth Matters
A fibroid growing more than 1cm every 6 months warrants closer monitoring and medical discussion. Rapid growth is a reason to accelerate treatment conversations — not necessarily because of malignancy risk (which is very low) but because the window for less invasive intervention closes as fibroids grow larger. For the full picture of diagnosis and monitoring, see our fibroid symptoms checklist.
