Uterine fibroids, also known as myomas, are noncancerous growths that develop in the muscular wall of the uterus.
They are composed of smooth muscle and fibrous tissue and are usually surrounded by a pseudocapsule that separates them from normal uterine muscle. Fibroids are strongly influenced by hormones and age, most commonly appearing in women between 30 and 40 years old. Because they depend on estrogen and progesterone, they often shrink and cause fewer symptoms after menopause. Importantly, fibroids are rarely cancerous.
The location of fibroids plays a major role in how they affect the body. Subserosal and intramural fibroids grow on the outer wall of the uterus and can enlarge the uterus considerably, sometimes to the size of a watermelon. These growths can cause abdominal pressure, frequent urination, constipation, or pain during intercourse, depending on the organs they press against. In rare cases, fibroids can also grow within the broad ligament next to the uterus. Submucosal fibroids, on the other hand, extend into the uterine cavity and are the most significant type because they often lead to heavy menstrual bleeding and anemia.
Fibroids are extremely common. In the United States, about 70% of women will develop them during their lifetime, with the highest prevalence seen in women between the ages of 50 and 54. African American women are disproportionately affected, with up to 80% developing fibroids, compared to around 40% of Caucasian women. Indian women also show high rates of fibroid development. Globally, prevalence varies widely. Eastern Europe reports some of the highest rates, with Latvia leading at 667 cases per 100,000 women, followed by Russia and Ukraine with more than 580 cases per 100,000. Latin America also has a high burden, particularly Brazil at over 500 cases per 100,000. Sub-Saharan Africa has similar numbers, while Australia and North Korea show much lower rates at around 100 cases per 100,000.
Several risk factors increase the likelihood of fibroids. Race is the most prominent, with African American women at the greatest risk. Older age, being premenopausal, family history, hypertension, and obesity are also linked to higher incidence. At the same time, certain factors appear protective.
Oral contraceptives and the use of depo-medroxyprogesterone acetate, especially when started after adolescence, can lower the risk of developing fibroids.
Fibroid symptoms vary widely. Heavy or prolonged menstrual bleeding is one of the most common complaints, especially when fibroids grow into the uterine cavity. This can lead to anemia, fatigue, and weakness, and in severe cases, fainting due to dangerously low hemoglobin levels. Large fibroids may make the abdomen appear distended, even resembling pregnancy, and can cause pressure on nearby structures. When the bladder is compressed, women often experience urinary frequency, sometimes as often as every half hour, with symptoms worsening at night. Pressure on the bowel can lead to constipation, and compression in the pelvis can cause discomfort during sexual activity.
Although fibroids usually do not cause pain, they may occasionally outgrow their blood supply, leading to degeneration and localized pain. Fertility can also be affected when fibroids block the fallopian tubes or prevent implantation of a fertilized egg. Even when conception occurs, fibroids can contribute to recurrent miscarriages, preterm labor, or restricted fetal growth due to poor placental support and limited space in the uterus.
Management depends on symptoms, severity, and a woman’s fertility goals. Some women find relief with over-the-counter medications such as ibuprofen or naproxen to ease menstrual discomfort. If anemia develops from heavy bleeding, iron supplements may be given orally, intravenously, or through blood transfusion in severe cases. Hormonal options include oral contraceptives, vaginal rings, or injections, which can help reduce bleeding. Hormonal intrauterine devices (IUDs) that release progesterone are especially effective in reducing menstrual flow and improving anemia, although copper IUDs are not recommended as they can worsen bleeding. Other medical options include tranexamic acid, taken only during menstruation to reduce bleeding, and newer medications such as GnRH antagonists and agonists, which shrink fibroids temporarily but are limited by menopausal side effects and bone loss when used long term.
When medication alone is insufficient, minimally invasive procedures are available. Radiofrequency ablation uses heat to shrink fibroids over several months, while endometrial ablation destroys the uterine lining and is suitable only for small fibroids, though it is not recommended for women who wish to become pregnant. Hysteroscopic resection, performed through the vagina, allows surgeons to shave fibroids inside the uterine cavity without skin incisions.
Another widely used technique is uterine artery embolization, also called uterine fibroid embolization. In this minimally invasive procedure, a radiologist inserts a catheter into the uterine arteries and releases tiny particles that block blood flow to fibroids, causing them to shrink. This procedure avoids surgical incisions, requires only a short hospital stay, and allows women to return to normal activities within one to two weeks.
Surgical options remain important, especially for women with severe symptoms or fertility concerns. Myomectomy, the surgical removal of fibroids, is the preferred option for those who wish to preserve fertility. It was once performed through large abdominal incisions but can now be done using laparoscopy or robotic surgery, which involves smaller incisions, faster recovery, and less blood loss. Hysterectomy, the complete removal of the uterus, is considered a last resort for women who do not wish to retain fertility. This operation is increasingly performed through minimally invasive or robotic techniques, allowing quicker recovery.
Finally, focused ultrasound surgery is an emerging treatment available in only a few centers. Using MRI guidance, ultrasound beams are directed through the skin to heat and destroy fibroids without damaging surrounding tissues.
Uterine fibroids are a common condition that can range from being completely symptom-free to severely disruptive. Fortunately, advances in medical and surgical care now offer a wide range of treatment options. The best approach depends on the woman’s symptoms, her age, her overall health, and whether she hopes to have children in the future.