Understanding Fibroids: Information Before Your Doctor Visit

What Fibroids Are and How They Develop

Uterine fibroids are noncancerous tumors that grow in or on the uterus. They are also called leiomyomas or myomas. Fibroids are extremely common—research shows that 70 to 80 percent of women will develop at least one fibroid by age 50. Despite their frequency, many women know little about them before receiving a diagnosis.

Fibroids develop from the smooth muscle cells of the uterus. Over time, a single cell begins to divide repeatedly, creating a firm, rubbery mass. Unlike cancer, fibroids do not spread to other parts of the body and rarely become malignant. They can range in size from as small as a grain of rice to as large as a grapefruit or even bigger. Some women have a single fibroid, while others develop multiple fibroids at the same time.

The exact cause of fibroids remains unclear, but researchers have identified several factors that appear to influence their development. Estrogen and progesterone—hormones that regulate the menstrual cycle—seem to play a role, since fibroids typically develop during reproductive years and often shrink after menopause when hormone levels drop. Genetic factors also matter; if your mother or sister had fibroids, your risk increases. African American women are two to three times more likely to develop fibroids than white women, and they tend to appear at younger ages and grow larger.

Fibroids are classified by their location in or on the uterus. Intramural fibroids grow within the muscular wall of the uterus. Submucosal fibroids develop just under the inner lining and protrude into the uterine cavity. Subserosal fibroids grow on the outer surface of the uterus and may extend into the pelvic area. Pedunculated fibroids are attached to the uterus by a thin stalk, either inside or outside.

Takeaway: Understanding that fibroids are common, noncancerous growths can reduce anxiety. Knowing your family history and ethnic background provides context for your risk level, which you can discuss with your doctor during your visit.

Recognizing Symptoms and When They Occur

Many women with fibroids experience no symptoms at all and discover them only during routine medical exams or imaging tests done for other reasons. Studies suggest that roughly 50 percent of women with fibroids have no symptoms. However, when symptoms do occur, they vary widely depending on the size, number, and location of the fibroids.

Heavy menstrual bleeding is the most commonly reported symptom, affecting about 30 percent of women with fibroids. Women may describe soaking through one or more pads or tampons per hour, needing to change protection during the night, or passing blood clots larger than a quarter. This excessive bleeding can continue for more than seven days and may lead to iron-deficiency anemia, causing fatigue, shortness of breath, or dizziness.

Pelvic pain and pressure are also frequent symptoms. Women report a feeling of heaviness or fullness in the lower abdomen or pelvis. Some describe sharp or stabbing pain, particularly during menstruation. The location and intensity of pain often correlate with fibroid size and position. Larger fibroids or those positioned near the pelvic nerves tend to cause more noticeable discomfort. Pain may worsen during the menstrual cycle or with certain physical activities.

Other symptoms can include urinary frequency or urgency, constipation or difficulty with bowel movements, lower back pain, and pain during sexual intercourse. Some women experience prolonged or frequent menstrual periods. If a fibroid is very large or positioned in a specific location, it may press against the bladder, causing increased trips to the bathroom, or against the bowel, leading to constipation. During pregnancy, fibroids may cause complications, though many pregnancies proceed without problems even when fibroids are present.

The timing of symptoms matters. Many women notice changes during their menstrual cycle—symptoms often intensify during the heaviest bleeding days. Some symptoms develop gradually over months or years, while others appear suddenly. Tracking when symptoms occur and their severity can provide valuable information to share with your doctor.

Takeaway: Keep a simple log of your symptoms for two to three months before your doctor visit. Record the dates of your period, the number of days of heavy bleeding, pain levels (on a scale of 1 to 10), and any other physical changes. This record helps your doctor understand your experience more clearly.

How Fibroids Are Diagnosed and What Tests Involve

Diagnosis typically begins during a pelvic exam. Your doctor may feel irregularities or lumps in the uterus that suggest fibroids. However, a physical exam alone cannot confirm fibroids or show their exact size and location. Additional imaging is needed for accurate diagnosis and to determine the best approach to treatment.

Transvaginal ultrasound is the most common imaging test for diagnosing fibroids. A thin probe about the width of a finger is gently inserted into the vagina, allowing the doctor to get a close, clear view of the uterus and fibroids. The entire procedure typically takes 15 to 30 minutes and involves no radiation. Most women find it tolerable, though it may feel uncomfortable. A transabdominal ultrasound, performed by moving a probe across the lower abdomen over the skin, may be done alongside or instead of the transvaginal approach, depending on what information is needed.

MRI (magnetic resonance imaging) provides the most detailed pictures of fibroids and is often used when surgery is being considered or when the number and exact locations of fibroids need to be mapped precisely. An MRI scan takes 30 to 60 minutes and involves lying still inside a machine that uses magnetic fields and radio waves to create detailed images. No radiation is used. Some women find the noise and enclosed space uncomfortable, but sedation can be provided if needed. MRI is particularly valuable when fibroids are numerous, when they're located in positions that make surgery complex, or when the doctor needs to distinguish between fibroids and adenomyosis (a different uterine condition).

In some cases, hysterosalpingography (HSG) or sonohysterography may be performed. These procedures involve injecting a dye or saline fluid into the uterus while taking X-rays or ultrasound images, allowing doctors to see how fibroids affect the uterine cavity. These tests are particularly relevant if infertility is a concern.

Blood tests are not used to diagnose fibroids but may be ordered to check for anemia if heavy bleeding has been occurring, or to assess overall health before considering treatment options.

Takeaway: Before your imaging appointment, ask which type of test is scheduled and what to expect. Write down any questions about the procedure. After results are available, request copies for your records and ask your doctor to explain what the images show about size, number, and location of fibroids.

Understanding Treatment Options and Their Trade-offs

Treatment decisions depend on several factors: whether symptoms are present and how bothersome they are, whether you want to preserve fertility, your age, the number and size of fibroids, and your personal preferences. No single treatment works best for everyone, and your doctor may discuss multiple options.

Watchful waiting is appropriate for many women, particularly those with no symptoms or mild symptoms. Your doctor may suggest monitoring fibroids with regular ultrasounds every year or two while taking no action. This approach is safe because fibroids rarely become cancerous. Many fibroids grow slowly or not at all. As women approach menopause, fibroids often stop growing or even shrink as hormone levels decline. If symptoms remain manageable, watching and waiting avoids the risks and recovery time of surgery.

Medications can reduce symptoms without removing fibroids. Over-the-counter pain relievers like ibuprofen or naproxen help with cramping and pain. Prescription medications called GnRH agonists (such as leuprolide or goserelin) temporarily shrink fibroids by lowering estrogen levels, but they work only while the medication is taken and often cause hot flashes and vaginal dryness. A newer medication called ulipristal acetate (ella) can shrink fibroids and reduce heavy bleeding. Birth control pills,