Uterine fibroids

Uterine fibroids (leiomyomas) are noncancerous growths of the uterus made of muscle and fibrous tissue. They are very common during the reproductive years and range from tiny seedlings to large masses that can distort the uterus. Many fibroids cause no symptoms and are found during pelvic exams or imaging. Others cause heavy menstrual bleeding, pelvic pressure, pain, or reproductive problems.

Fibroids are hormone-responsive and often shrink after menopause. Treatment is individualized based on symptoms, fibroid size and location, age, and desire for future pregnancy. Options range from watchful waiting and medicines to minimally invasive procedures and surgery.

Symptoms, when present, may include:

• Heavy or prolonged menstrual periods (menorrhagia)
• Menstrual blood clots and anemia-related fatigue
• Pelvic pressure or fullness
• Frequent urination or difficulty emptying the bladder
• Constipation
• Backache or leg pains
• Pain during intercourse
• Enlarged abdomen or a palpable mass
• Reproductive issues — difficulty conceiving or pregnancy complications in some cases

Submucosal fibroids (projecting into the uterine cavity) are most associated with heavy bleeding; large intramural or subserosal fibroids more often cause bulk symptoms.

The exact cause is unknown. Fibroids arise from a single uterine smooth-muscle cell that multiplies. Estrogen and progesterone promote growth; fibroids often enlarge during reproductive years and shrink after menopause. Genetic changes within fibroid cells, growth factors, and extracellular matrix abnormalities contribute. Family history and race influence risk, suggesting both genetic and environmental factors.

Risk factors include:

• Age — most common in 30s and 40s
• African ancestry — higher prevalence, earlier onset, and often more severe disease
• Family history of fibroids
• Obesity
• Early onset of menstruation
• Vitamin D deficiency in some studies
• Diet high in red meat and low in green vegetables in observational research
• Never having given birth (in some studies)

Possible complications include:

• Iron-deficiency anemia from chronic heavy bleeding
• Chronic pelvic pain
• Urinary tract obstruction or hydronephrosis from very large fibroids (uncommon)
• Infertility or recurrent pregnancy loss when fibroids distort the cavity
• Pregnancy complications — preterm birth, malpresentation, cesarean delivery, postpartum hemorrhage
• Rare acute pain from degeneration or torsion of a pedunculated fibroid
• Very rarely, malignant transformation (leiomyosarcoma is usually a separate entity rather than transformation of a known fibroid)

Fibroids cannot be reliably prevented. Maintaining a healthy weight, adequate vitamin D, and a balanced diet may modestly influence risk. Hormonal contraceptives sometimes reduce menstrual bleeding associated with fibroids even if they do not shrink them substantially.

Evaluation typically includes:

• Pelvic examination — enlarged or irregular uterus
• Pelvic ultrasound — first-line imaging to confirm fibroids and assess size/location
• Sonohysterography or hysteroscopy for submucosal fibroids
• MRI when anatomy is complex, when intervening radiologically, or when adenomyosis must be distinguished
• Complete blood count for anemia
• Endometrial sampling when abnormal bleeding patterns raise concern for hyperplasia or cancer (especially after age 45 or with risk factors)

See a clinician for heavy periods that interfere with life, pelvic pain or pressure, difficulty with urination or bowel movements, or concerns about fertility. Seek prompt care for severe pelvic pain, very heavy bleeding with lightheadedness, or symptoms of severe anemia.

Treatment depends on symptoms, fibroid characteristics, and reproductive plans:

Watchful waiting — for asymptomatic or mildly symptomatic fibroids, especially near menopause.

Medications

• NSAIDs for pain
• Tranexamic acid for heavy menstrual bleeding
• Hormonal options — combined oral contraceptives, progestin IUDs, progestin injections, or GnRH agonists/antagonists (with add-back therapy) to shrink fibroids temporarily or control bleeding
• Iron supplementation for anemia

Procedures

• Uterine artery embolization
• MRI-guided focused ultrasound (selected cases)
• Radiofrequency ablation
• Myomectomy (hysteroscopic, laparoscopic/robotic, or open) when fertility preservation is desired
• Hysterectomy — definitive treatment when childbearing is complete and symptoms are significant

Shared decision-making weighs symptom relief, recovery time, and impact on future pregnancy.

Helpful measures:

• Use a heating pad for cramps
• Track menstrual flow and symptoms
• Take iron if prescribed and eat iron-rich foods
• Maintain a healthy weight
• Attend follow-up imaging as recommended
• Discuss contraception and pregnancy plans with your clinician when fibroids are present
• Report sudden severe pain or very heavy bleeding promptly

Bring:

• Menstrual diary (flow amount, duration, pain, clots)
• Prior ultrasound or MRI reports
• List of medicines and prior treatments
• Pregnancy plans and priorities (uterus-sparing vs definitive treatment)
• Questions about medical vs procedural options and recovery