Overview
Uterine fibroids (leiomyomas) are non-cancerous growths of muscle and fibrous tissue that develop in or on the uterus. They are extremely common and most cause no symptoms. When symptomatic, they cause heavy menstrual bleeding, pelvic pain and pressure, urinary frequency, and sometimes difficulty conceiving. They are not cancer and do not become cancer.
How common is it?
Fibroids affect up to 70 to 80% of women by age 50. About 25 to 30% have symptoms significant enough to seek treatment. They are more common and tend to be more severe in women of African and Caribbean descent.
Causes and risk factors
Fibroids arise from single smooth muscle cells in the uterine wall that undergo a genetic mutation and grow under oestrogen and progesterone stimulation.
Common risk factors
- Age (increase from puberty, peak in 40s, shrink after menopause)
- Female sex and oestrogen exposure
- Black African or Caribbean ethnicity (3 to 5 times higher risk, more severe)
- Family history of fibroids
- Obesity (adipose tissue increases circulating oestrogen)
- Never having been pregnant
- Vitamin D deficiency (associated with higher risk)
- Diet high in red meat
Symptoms
- Most fibroids: no symptoms (found incidentally on ultrasound or during pelvic examination)
- Heavy, prolonged, or painful periods
- Pelvic pressure, pain, or bloating
- Urinary frequency or urgency from bladder compression
- Constipation from rectal pressure
- Abdominal distension
- Painful intercourse
- Difficulty conceiving or recurrent miscarriage (submucosal fibroids)
When to see a doctor
See a GP for heavy periods significantly affecting daily life, pelvic pain, or a rapidly growing uterus. Sudden severe abdominal pain may indicate fibroid degeneration (particularly in pregnancy).
Diagnosis
Pelvic ultrasound is the primary investigation. MRI delineates fibroid number, size, and location more precisely (essential before surgical or uterine artery embolisation planning). Hysteroscopy for submucosal fibroids.
Treatments
Conservative management
Watchful waiting for asymptomatic or mildly symptomatic fibroids. NSAIDs reduce period pain. Tranexamic acid reduces menstrual blood loss by 30 to 50%. Combined oral contraceptive pill reduces menstrual blood loss.
Hormonal treatment and GnRH agonists
Levonorgestrel IUS (Mirena) reduces menstrual blood loss and is often tried first. GnRH agonists (goserelin, leuprorelin) shrink fibroids by inducing medical menopause — effective short-term, used to prepare for surgery. Relugolix combination tablet is a new licensed oral option.
Uterine artery embolisation (UAE)
Interventional radiology procedure that blocks blood supply to fibroids, causing them to shrink. Preserves the uterus. Success rates 85 to 90% for symptom improvement. Recovery 1 to 2 weeks.
Myomectomy
Surgical removal of fibroids preserving the uterus. Preferred for women wishing to conceive. Laparoscopic or hysteroscopic approaches for suitable fibroids. Fibroids may recur.
Hysterectomy
Definitive treatment eliminating fibroid recurrence. Appropriate for women who have completed their family and prefer a permanent solution. Laparoscopic hysterectomy is now standard.
Self-care and lifestyle
- A low-fat, plant-based diet and maintaining a healthy weight reduce fibroid risk and growth
- Regular aerobic exercise reduces oestrogen levels
- Ensure adequate vitamin D (sun exposure and supplementation)
- Monitor symptoms with a menstrual diary to assess treatment response
Prevention
No reliable prevention, but maintaining a healthy weight, regular exercise, and adequate vitamin D may reduce risk. Parity (having children) is protective.