Uterine Fibroids

Contents

1. What fibroids are made of
2. Position shapes the symptoms
3. Who develops fibroids
4. Treatment runs from watching to surgery

The word fibroid names a growth by its fibrous look, and the clinical name, leiomyoma, is built from the Greek for smooth, muscle and tumor, which describes these common growths of the uterus more exactly; they sit among the menstrual disorders and pelvic health concerns Candace Cooley has treated as an obstetrician and gynecologist. Both names are accurate in their way. The growths are firm, and under the microscope they are mostly muscle. Neither name says the most useful thing about them, which is that they are benign and that their position in the uterus does much to decide what they do.

What fibroids are made of

The National Institute of Child Health and Human Development describes fibroids as growths of smooth muscle cells, fibroblasts and other material that form in or on the wall of the uterus.¹ They can appear singly or in clusters, a single uterus often holds several of different sizes, and over time they may grow, shrink or stay the same.¹ A gynecologist quoted by CBS News calls them the most common tumor in women, arising during the reproductive years from a cause that is still unknown.⁶ The same physician notes that they occur in women of every background and income level, and that some women simply develop them without any identifiable reason.⁶

The word tumor alarms people, and it seldom should here. NPR reports that fewer than one in a hundred fibroids are cancerous, and quotes an obstetrician who has seen patients agree to major surgery partly because they heard the word and assumed the worst.³ Many women with fibroids never notice them; NPR puts the share who struggle with heavy bleeding, frequent urination and pain at roughly a quarter to a half.³ For those who do, the effects can be serious. The CBS report describes a young woman whose bleeding was heavy enough to make her faint and to require a blood transfusion, and the USC Center for Health Journalism profiles another who bled for almost a month before a transfusion of her own.⁶⁴

Figure

Where fibroids grow

1. 01
   SubmucosalJust beneath the uterine lining, bulging into the cavity of the uterus.
2. 02
   IntramuralWithin the muscle layers of the uterine wall.
3. 03
   SubserosalOn the outer surface of the uterus.
4. 04
   PedunculatedOn a stalk, growing out from the surface or into the cavity.

Position shapes the symptoms

The NICHD sorts fibroids by where they grow. Submucosal fibroids lie just beneath the lining and push into the cavity of the uterus; intramural fibroids sit within the muscle of the wall; subserosal fibroids grow on the outer surface; and pedunculated fibroids hang from a stalk, either outward from the surface or inward into the cavity.¹ Each position brings its own tendencies. A growth that distorts the cavity sits close to the lining that sheds each month, while one on the outer surface can press on neighboring organs.

Symptoms, the CBS report notes, vary with both size and location.⁶ Heavy periods are the most frequent complaint, and some fibroids grow large enough to press on the bladder or to be felt as a firm lump in the abdomen.⁶ NPR adds that symptomatic fibroids can bring pelvic pain, frequent urination and, in turn, depression and lost working time.³ The MedlinePlus overview of uterine diseases lists fibroids among the causes of uterine problems and notes that the first sign is often abnormal bleeding, between periods, unusually heavy, or lasting longer than usual.⁵ Finding the cause usually begins with a history and pelvic examination, followed where needed by blood tests, imaging or a biopsy.⁵ When a submucosal growth is suspected, the inside of the uterus can be examined directly, the subject of the entry on hysteroscopy.

Who develops fibroids

Fibroids are extremely common. MedPage Today, summarizing the background of a 2026 study, states that they affect 70 to 80 percent of women by age 50.⁷ The CBS report gives figures by group: 80 percent of Black women are diagnosed by age 50, against 70 percent of white women.⁶

Figure

Share of women diagnosed with fibroids by age 50

• White women70
• Black women80

The NICHD lists the factors associated with higher risk: older age within the reproductive years, African American race, obesity, a family history of fibroids, high blood pressure, never having been pregnant, vitamin D deficiency, food additives and soybean milk.² The risk factor page also reports research suggesting that fibroids may get smaller once menopause has passed, though less often in Black women, in whom fibroids typically develop earlier, grow larger and cause more severe symptoms.²

The USC Center for Health Journalism cites research finding Black women two to three times more likely than white women to develop fibroids, with about 60 percent affected by age 35 compared with about 40 percent of white women, and one study finding nearly 22 percent of Chinese American women affected. The same research suggests that Black women tend to develop fibroids at younger ages and to have larger and more numerous growths.⁴ It quotes Erica Marsh of the University of Michigan that vitamin D levels, obesity, chronic stress and hair relaxer exposure have all been examined, yet none has been proven to cause fibroids.⁴ NPR adds that research still cannot say why Black women are more susceptible.³

Family history runs through many of the published accounts. One advocate quoted by NPR began bleeding heavily at 14, while her mother and grandmother had both had fibroids, yet the family assumed she was too young to have them; she later had two operations to remove them.³ An obstetrician in the same report says she wishes more women knew their family history and understood that heavy bleeding is not normal.³

Treatment runs from watching to surgery

Because many fibroids cause no trouble, not every one needs treatment. When they do cause symptoms, NPR reports that clinicians weigh the number, size, type and location of the fibroids together with how severe the symptoms are and what the patient wants for the future.³ The CBS report makes the same point from the other side: options for a younger woman planning a family can differ from those for a woman close to menopause.⁶

The options include medicines that ease heavy bleeding, newer drugs that shrink the growths, and procedures that remove or destroy the fibroids while keeping the uterus.³ Myomectomy, the surgical removal of fibroids, preserves the uterus; hysterectomy removes it. According to NPR, severe fibroid symptoms account for more hysterectomies in the United States than any other cause, Black women undergo the operation at no less than double the rate of white women, and one researcher has found it historically overused.³

The authors of the MedPage study call hysterectomy the definitive treatment but note that it is unsuitable for anyone wishing to keep the uterus and that it has been linked to longer term cardiovascular and metabolic risks, particularly in younger women.⁷

Figure

Two uterus preserving procedures compared

	Laparoscopic radiofrequency ablation	Myomectomy
What it does	Heats the center of the fibroid, which then shrinks over time	Removes the whole fibroid, by laparoscopy or open surgery
Patients in the study	237	164
Symptom change over two years	Large and sustained improvement	Large and sustained improvement, slightly greater at first
Later births	Leaves the option of vaginal birth	Nearly always followed by cesarean birth

That study compared two uterus preserving procedures in 401 women at centers across the United States. Laparoscopic radiofrequency ablation heats the center of a fibroid so that it shrinks over time, while myomectomy removes the fibroid entirely. Both produced large and lasting improvements in symptoms and quality of life over two years; myomectomy held a small early edge that fell short of clinical importance and had disappeared by 24 months.⁷ Just over half the participants were Black, a group often underrepresented in such research. The authors noted that the study was not randomized and that the two groups differed at the outset.⁷ The choice between the procedures can turn on later plans: after radiofrequency ablation a vaginal birth remains possible, while nearly all women who have had a myomectomy go on to deliver by cesarean birth.⁷

The range of options also depends on who is offering them. Erica Marsh told NPR that clinicians tend to grow comfortable with one familiar treatment and fall back on it, and that every patient arrives with her own symptoms, goals and fears.³

Fibroids can also return after removal. Both women profiled by the USC center saw their fibroids return years after surgery and needed further treatment.⁴ Which path suits any one woman, from watchful waiting to surgery, is a decision she makes with her own clinician. For most women the symptom that brings fibroids to attention is bleeding, and the next entry, on heavy menstrual bleeding, looks at that symptom on its own terms. Pain with the period can have other sources as well, among them endometriosis.