ConditionWomen's & pregnancy health
Uterine Fibroids: Symptoms, Causes and Treatment
Uterine fibroids are noncancerous growths of muscle and fibrous tissue in the wall of the uterus. They are extremely common: up to 70 to 80% of women have them by age 50, and they are more common and often more severe in Black women. Many cause no symptoms. Others cause heavy or long periods, anemia, pelvic pressure, frequent urination or fertility problems. Treatment depends on symptoms, size, location and pregnancy plans, and ranges from medicines to procedures that remove or shrink fibroids.
Also called: Leiomyomas, myomas, fibromyomas, uterine leiomyomas, fibroids
At a glance
- What they are
- Benign (noncancerous) muscle tumors of the uterus, from seed-sized to larger than a grapefruit.
- How common
- Most common pelvic tumor in women; most have no symptoms.
- Main symptoms
- Heavy, long periods, anemia, pelvic pressure, bloating, frequent urination, back pain.
- Diagnosis
- Pelvic exam and ultrasound; MRI or saline sonohysterography for planning.
- Treatment
- Watchful waiting, hormonal and non-hormonal medicines, embolization, myomectomy or hysterectomy.
When to get help
Call 911 or go to the ER
- Soaking through one or more pads or tampons every hour for 2 hours or more, or passing large clots with dizziness or fainting
- Sudden severe pelvic pain with fever or vomiting (possible degenerating or twisted fibroid)
- Being unable to pass urine
See a doctor within a day or two
- Heavy bleeding with tiredness, breathlessness or a racing heart (possible anemia)
- Rapid growth of a known fibroid, especially after menopause
- Any vaginal bleeding after menopause
- Severe pain or bleeding during pregnancy
Book a routine appointment
- Periods lasting more than 7 days or needing double protection
- Bleeding between periods
- Pelvic pressure, a swollen lower belly, frequent urination or constipation
- Trouble getting pregnant or repeated miscarriages
Usually safe to manage at home
- Known small fibroids without symptoms: no treatment needed, routine checkups
- Mild period pain: heat, and ibuprofen or naproxen following the label dose
What are uterine fibroids?
Fibroids (leiomyomas) grow from a single smooth muscle cell in the uterine wall that multiplies abnormally. They are firm, round and usually multiple. Their growth depends on the hormones estrogen and progesterone, so they:
- Rarely appear before puberty
- Grow during the reproductive years and sometimes during pregnancy
- Usually shrink after menopause
They are almost never cancer. A rare cancer called leiomyosarcoma can look similar, but it is not thought to develop from fibroids.
Types of fibroids by location
Location matters more than size for symptoms and treatment.
| Type | Where | Typical effects |
|---|---|---|
| Submucosal | Bulging into the uterine cavity | Heavy bleeding, infertility, miscarriage, even when small |
| Intramural | Within the muscle wall | Heavy periods, pressure, larger uterus; the most common type |
| Subserosal | On the outer surface | Pressure on bladder or bowel, back pain; little effect on bleeding |
| Pedunculated | Attached by a stalk, inside or outside | Can twist and cause sudden pain |
| Cervical | In the cervix | Pressure, pain with sex, difficulty in birth |
Doctors use the FIGO classification (types 0 to 8) to describe exact position.
Symptoms of fibroids
About 1 in 4 women with fibroids has symptoms. These include:
Bleeding
- Heavy menstrual bleeding, sometimes with clots
- Periods lasting more than 7 days
- Bleeding between periods
- Iron deficiency anemia: tiredness, breathlessness, pale skin
Pressure and bulk symptoms
- Pelvic pain or pressure, a feeling of fullness
- A swollen or firm lower belly, sometimes looking pregnant
- Frequent urination or difficulty emptying the bladder
- Constipation
- Lower back or leg pain
- Pain during sex
Fertility and pregnancy
Submucosal fibroids and those distorting the cavity can reduce fertility and raise miscarriage risk.
Causes and risk factors
The exact cause is unknown, but genetic changes in uterine muscle cells and hormones both play a role. Risk factors include:
- Age 30 to 50
- Black race: fibroids start earlier, are more numerous and larger, and cause more symptoms
- Family history
- Early first period
- Obesity
- Vitamin D deficiency
- High blood pressure
- Diet high in red meat and alcohol
Having children and long-term use of hormonal contraception are linked to lower risk.
Fibroids vs adenomyosis vs polyps
| Fibroids | Adenomyosis | Endometrial polyps | |
|---|---|---|---|
| What | Distinct muscle lumps | Lining tissue growing into the muscle wall | Soft growths of the lining |
| Uterus | Lumpy, irregular enlargement | Evenly enlarged, boggy | Usually normal size |
| Main symptoms | Heavy bleeding, pressure | Painful, heavy periods | Irregular bleeding, spotting |
| Treatment | Can be removed individually | Harder to remove; hormones or hysterectomy | Removed by hysteroscopy |
The conditions often occur together.
Diagnosis
- Pelvic exam: an enlarged, irregular uterus
- Ultrasound: transvaginal and abdominal, the main test
- Saline infusion sonohysterography or hysteroscopy: shows fibroids inside the cavity
- MRI: maps size, number and position before procedures, and helps distinguish from adenomyosis or rare sarcoma
- Blood count and ferritin to check for anemia
Treatment
No treatment is needed for fibroids without symptoms. They are monitored, and most shrink after menopause.
Medicines for heavy bleeding and pain
- NSAIDs such as ibuprofen or naproxen, following the label dose, reduce pain and modestly reduce bleeding
- Tranexamic acid, a non-hormonal tablet taken during periods, reduces blood loss
- Hormonal options: combined birth control pills, the levonorgestrel IUD (best when the cavity is not distorted), or progestins
- Oral GnRH antagonists with add-back hormone therapy (such as relugolix combination or elagolix combination): reduce bleeding significantly and can be used longer-term
- GnRH agonists (such as leuprolide injections) shrink fibroids temporarily, often before surgery; they cause menopausal symptoms and bone loss
- Iron supplements for anemia
Medicines control symptoms but do not remove fibroids, and symptoms usually return after stopping.
Procedures that keep the uterus
- Hysteroscopic myomectomy: submucosal fibroids are shaved out through the cervix, with no incisions. Quick recovery.
- Laparoscopic or robotic myomectomy: keyhole removal of fibroids in the wall or on the surface.
- Abdominal myomectomy: open surgery for large or numerous fibroids.
- Uterine fibroid embolization (UFE): an interventional radiologist blocks the blood supply through a catheter from the wrist or groin. Fibroids shrink over months. Recovery is about 1 to 2 weeks.
- Radiofrequency ablation: heat destroys fibroids through a laparoscopic or transcervical approach.
- MRI-guided focused ultrasound: noninvasive heat treatment for selected fibroids.
New fibroids can grow after any uterus-sparing treatment, so some people need further treatment.
Hysterectomy
Removing the uterus is the only permanent cure. It is suitable for people who have finished having children and have significant symptoms. Many are done laparoscopically or vaginally. The ovaries can usually be kept.
Choosing a treatment
| Your priority | Options often considered |
|---|---|
| Heavy bleeding, fibroids small or wall-based | Tranexamic acid, hormonal IUD, oral GnRH antagonist |
| Submucosal fibroid, wants pregnancy | Hysteroscopic myomectomy |
| Large fibroids, wants pregnancy | Myomectomy |
| Wants to avoid surgery, no pregnancy plans | UFE, radiofrequency ablation, medicines |
| Wants a permanent solution | Hysterectomy |
Fibroids and pregnancy
Most people with fibroids have normal pregnancies. Fibroids can sometimes cause:
- Pain from "red degeneration," when a fibroid outgrows its blood supply, usually in the second trimester
- Higher rates of miscarriage, preterm birth, breech position and cesarean birth, mainly with large or submucosal fibroids
- Heavier bleeding after birth
After myomectomy, a cesarean may be recommended if the uterine wall was opened deeply.
Complications
- Iron deficiency anemia from heavy bleeding
- Urinary retention and kidney swelling from pressure (rare)
- Infertility and pregnancy complications
- Acute pain from degeneration or a twisted stalk
Frequently asked questions
What are the first signs of fibroids?
The most common early sign is heavier or longer periods, sometimes with clots. Others include pelvic pressure, a feeling of fullness or bloating in the lower belly, needing to urinate more often, and tiredness from anemia. Many fibroids cause no symptoms and are found on a routine exam or scan.
Do fibroids need to be removed?
No, not if they cause no symptoms. Fibroids are benign and usually shrink after menopause. Treatment is recommended when they cause heavy bleeding, anemia, pain, pressure, or fertility problems. The best option depends on your symptoms, the fibroids' size and location, and whether you want a future pregnancy.
Can fibroids turn into cancer?
Fibroids are almost never cancer, and they are not believed to turn into cancer. A rare uterine cancer called leiomyosarcoma can look similar on scans. Rapid growth, especially after menopause, should be checked. Your doctor considers this risk when choosing between treatment methods, particularly before procedures that break up tissue.
Can you get pregnant with fibroids?
Yes. Most people with fibroids conceive and have healthy pregnancies. Submucosal fibroids that bulge into the uterine cavity can reduce fertility and increase miscarriage risk, and removing them improves pregnancy rates. Wall and surface fibroids usually have less effect.
Do fibroids go away after menopause?
Usually they shrink after menopause because estrogen and progesterone levels fall, and symptoms often improve. Hormone therapy may keep them from shrinking. New growth or new bleeding after menopause is not typical of fibroids and needs prompt evaluation.
What size of fibroid needs surgery?
There is no single size cutoff. Symptoms and location matter more than size. A small submucosal fibroid can cause heavy bleeding and need removal, while a large surface fibroid may cause no problems. Very large fibroids that press on the bladder or bowel are more likely to need treatment.
Sources
This guide was written from current patient and clinical guidance, including:
- American College of Obstetricians and Gynecologists (ACOG): Uterine Fibroids FAQ
- ACOG: Practice Bulletin No. 228: Management of Symptomatic Uterine Leiomyomas
- Office on Women's Health (HHS): Uterine fibroids
- National Institute of Child Health and Human Development: Uterine Fibroids
- MedlinePlus: Uterine Fibroids