What Is a Myoma? Causes, Symptoms, and Treatment Options

Key Takeaways

• A myoma (also called a uterine fibroid or leiomyoma) is a noncancerous growth that develops from the smooth muscle tissue of the uterus. It is the most common benign tumor in women of reproductive age.
• Many myomas cause no symptoms at all and are discovered incidentally during a routine pelvic exam or imaging. When symptoms do occur, the most common are heavy menstrual bleeding, pelvic pain or pressure, and frequent urination.
• Treatment depends on severity and ranges from watchful waiting and medication to minimally invasive procedures and surgery. Most myomas do not require intervention unless they cause significant symptoms or affect fertility.

If you’ve been told you have a myoma, your first reaction was probably a mix of confusion and concern. The term sounds clinical and unfamiliar, even though the condition it describes is remarkably common. Up to 70% of white women and more than 80% of Black women are diagnosed with at least one myoma by the time they reach menopause, according to a review in Seminars in Reproductive Medicine.

Despite being so prevalent, myomas are often poorly explained at the point of diagnosis. Many women leave their appointments unsure whether their myoma needs treatment, whether it could become cancerous, or whether it will affect their ability to have children. This article answers those questions directly — covering what is a myoma, why it develops, the symptoms it can cause, how it’s diagnosed, and the full range of treatment options available.

What Is a Myoma?

A myoma — clinically known as a uterine leiomyoma or fibroid — is a benign (noncancerous) tumor that originates from the smooth muscle cells of the uterine wall (the myometrium). These growths are made up of muscle and connective tissue and can range in size from microscopic seedlings to large masses that distort the shape and size of the uterus.

A uterine myoma can develop as a single nodule or in clusters. Some women have one small growth they never know about, while others develop multiple fibroids that cause the uterus to expand significantly. The FDA notes that myomas can be as small as an apple seed or as large as a grapefruit, and in rare cases, even larger.

The overwhelming majority of myomas are benign. A review in Endocrine Reviews confirmed that in premenopausal women, over 99.7% of uterine leiomyomas are noncancerous, and the condition is not associated with an increased risk of uterine cancer. Myomas are hormone-dependent, meaning their growth is primarily driven by estrogen and progesterone, which is why they tend to develop during reproductive years and typically shrink after menopause when hormone levels decline.

Types of Uterine Myomas

Myomas are classified based on where they grow in relation to the uterine wall. The location of a uterine myoma determines which symptoms it causes and which treatment options are most appropriate.

Intramural Myomas

Intramural myomas grow within the muscular wall of the uterus and are the most common type, accounting for the majority of diagnosed fibroids. Because they are embedded in the myometrium, they can expand the uterus as they grow, sometimes making the abdomen appear enlarged. When they become large enough, intramural myomas can cause heavy menstrual bleeding, prolonged periods, pelvic pressure, and a sensation of fullness in the lower abdomen.

Subserosal Myomas

Subserosal myomas develop on the outer surface of the uterus and grow outward into the pelvic cavity. Because they extend away from the uterine lining, they are less likely to affect menstrual bleeding directly. However, they can press on surrounding structures, leading to symptoms like lower back pain, frequent urination when the bladder is compressed, or constipation when the rectum is affected. Very large subserosal myomas can also cause visible abdominal distortion.

Submucosal Myomas

Submucosal myomas grow into the inner cavity of the uterus, just beneath the endometrial lining. They are the least common type but tend to cause the most significant symptoms relative to their size. Even a small submucosal myoma can lead to disproportionately heavy or prolonged menstrual bleeding and is the type most closely associated with fertility problems, including difficulty with implantation and an increased risk of early pregnancy loss.

Pedunculated Myomas

Pedunculated myomas are attached to the uterus by a narrow, stalk-like structure called a peduncle rather than growing directly from the uterine wall. They can develop on the outer surface of the uterus (pedunculated subserosal) or project into the uterine cavity (pedunculated submucosal). If the stalk twists, it can cut off blood supply to the fibroid and cause sudden, sharp pelvic pain that may require urgent medical attention.

What Causes a Myoma?

The exact cause of myomas is not fully established, but research has identified several contributing factors. A systematic review analyzed data from 60 studies and found that both incidence and prevalence vary widely depending on population and diagnostic method, with rates ranging from 4.5% to 68.6%.

Hormones: Estrogen and progesterone promote the growth of myomas. This is why fibroids tend to grow during the reproductive years and often shrink after menopause. Conditions that increase estrogen exposure — such as obesity, early onset of menstruation, and hormone replacement therapy — are associated with higher risk.

Genetics: Myomas tend to run in families. If a woman’s mother had fibroids, her risk of developing them is approximately three times higher than average. Genomic research has identified recurrent mutations in the MED12 gene in 45–90% of uterine fibroids, depending on ethnicity.

Race: Black women are disproportionately affected by myomas, with earlier onset, larger tumors, and more severe symptoms compared to other racial groups. The reasons are believed to involve a combination of genetic, hormonal, and environmental factors.

Other risk factors: Additional factors linked to increased risk include obesity, vitamin D deficiency, high blood pressure, a diet high in red meat and low in fruits and vegetables, and alcohol consumption. Conversely, factors associated with a reduced risk include higher parity (having given birth), physical activity, and the use of combined oral contraceptives.

Symptoms of a Uterine Myoma

Many women with myomas experience no symptoms at all — an estimated 70–75% of cases are asymptomatic. When symptoms do occur, they are directly related to the size, number, and location of the growths.

• Heavy or prolonged menstrual bleeding is the most commonly reported symptom. Periods may last longer than a week, and blood loss can be heavy enough to cause iron-deficiency anemia.
• Pelvic pain and pressure may feel like a constant heaviness or fullness in the lower abdomen, particularly if the myomas are large or numerous.
• Frequent urination results when a myoma presses against the bladder. In some cases, it may also cause difficulty emptying the bladder completely.
• Constipation or rectal pressure can occur when a myoma grows toward the back of the uterus and presses on the rectum.
• Pain during intercourse is possible, especially with submucosal or intramural myomas that alter the shape of the uterine cavity.
• Lower back pain may develop when large subserosal myomas press on spinal nerves.
• Reproductive complications including difficulty conceiving, increased risk of miscarriage, and pregnancy complications can occur, particularly with submucosal myomas that distort the uterine cavity.

How Is a Myoma Diagnosed?

Myomas are most often detected during a routine pelvic exam, where a healthcare provider may feel an irregularly shaped or enlarged uterus. If myomas are suspected, the following imaging and diagnostic tools are commonly used to confirm the diagnosis and assess size, number, and location.

• Pelvic ultrasound is the first-line imaging method and uses sound waves to create a picture of the uterus. It can be performed abdominally or transvaginally and is highly sensitive for detecting fibroids.
• Sonohysterography involves injecting a small amount of saline into the uterus during an ultrasound to improve visualization of the uterine cavity, which is particularly helpful for identifying submucosal myomas.
• MRI provides the most detailed imaging of myomas and is often used when surgery is being planned, as it maps the exact size, number, and location of all fibroids.
• Hysteroscopy involves inserting a thin, lighted scope through the cervix into the uterus. It is used both diagnostically and, in some cases, therapeutically to remove submucosal myomas.
• Blood tests may be ordered to check for iron-deficiency anemia (from heavy bleeding) or to rule out other conditions such as thyroid disorders that can cause similar symptoms.

Treatment Options for Uterine Myomas

Treatment depends on the severity of symptoms, the size and location of the myomas, and whether the patient plans to become pregnant in the future. A review in StatPearls notes that only 10–20% of uterine fibroid cases require treatment, and the approach should be individualized based on the patient’s priorities.

Watchful Waiting

For women with small, asymptomatic myomas, active monitoring without treatment is often the recommended first step. Regular check-ups and periodic imaging allow providers to track whether the fibroids are growing or beginning to cause symptoms.

Medications

Several medications can help manage symptoms without removing the fibroids. NSAIDs (like ibuprofen) reduce menstrual pain. Hormonal treatments — including oral contraceptives, progestin-releasing IUDs, and GnRH agonists — can reduce bleeding and, in some cases, temporarily shrink fibroids. Newer oral medications like GnRH antagonists (such as elagolix and relugolix) have also been approved for managing heavy menstrual bleeding associated with fibroids.

Minimally Invasive Procedures

Uterine artery embolization (UAE) blocks blood flow to the fibroids, causing them to shrink. It is a nonsurgical option with a shorter recovery time than traditional surgery, though it is generally not recommended for women who plan to become pregnant.

MRI-guided focused ultrasound uses targeted sound waves to destroy fibroid tissue. It is noninvasive and performed on an outpatient basis, though it may not be appropriate for all fibroid types or locations.

Radiofrequency ablation uses heat delivered through a small needle to destroy fibroid tissue from within, causing the fibroids to shrink over time.

Surgical Options

Myomectomy removes fibroids while preserving the uterus and is the preferred option for women who wish to retain fertility. It can be performed through open surgery, laparoscopy, or hysteroscopy depending on the type and location of the fibroids. New fibroids can develop after myomectomy.

Hysterectomy — the surgical removal of the uterus — is the only definitive cure for uterine myomas and eliminates any possibility of recurrence. It is typically considered when symptoms are severe, other treatments have been ineffective, or the patient does not plan future pregnancies.

When to Contact a Healthcare Provider

Most myomas do not require emergency care, but certain symptoms warrant prompt medical evaluation. Contact a healthcare provider if you experience menstrual bleeding heavy enough to soak through a pad or tampon every hour, pelvic pain that is sudden, severe, or persistent, difficulty urinating, or signs of anemia such as extreme fatigue, dizziness, or shortness of breath. If you suspect you may be pregnant and have been previously diagnosed with fibroids, let your provider know early, as fibroids can occasionally affect pregnancy outcomes.

Conclusion

A myoma is an extremely common, noncancerous growth of the uterus that most women will encounter at some point during their reproductive years. For the majority, it causes no symptoms and requires no treatment. For those who do experience heavy bleeding, pelvic pressure, pain, or fertility challenges, there is a wide range of options — from medication and watchful waiting to minimally invasive procedures and surgery — that can be tailored to individual symptoms and goals.

The most important step is having a clear picture of what you’re dealing with. If you’ve been diagnosed with a uterine myoma or are experiencing symptoms that concern you, a conversation with your healthcare provider can help determine whether treatment is needed and which approach makes the most sense for your situation.

Frequently Asked Questions

Is a myoma the same as a fibroid?

Yes. Myoma, fibroid, leiomyoma, and fibromyoma are all terms used to describe the same condition — a noncancerous growth that develops from the smooth muscle of the uterus. The terms are used interchangeably in medical settings.

Can a myoma become cancerous?

It is extremely rare. Over 99.7% of uterine myomas are benign. A cancerous form called leiomyosarcoma can develop in the uterus but is not believed to arise from an existing benign fibroid. Rapid growth or postmenopausal bleeding should be evaluated promptly.

Can you get pregnant with a myoma?

Many women with myomas conceive and carry pregnancies without complications. However, submucosal myomas that grow into the uterine cavity can interfere with implantation or increase the risk of miscarriage. If fertility is a concern, a provider can assess whether the fibroid’s size and location warrant treatment before conception.

Do myomas go away on their own?

Myomas often shrink after menopause as estrogen and progesterone levels decline. During the reproductive years, some small myomas remain stable or grow slowly, while others may enlarge significantly. They do not typically resolve without hormonal change or intervention.