Uterine fibroids (leiomyomata) are noncancerous growths that develop in or just outside a woman’s uterus (womb). Uterine fibroids develop from normal uterus muscle cells that start growing abnormally. As the cells grow, they form a benign tumor.

Who Gets Uterine Fibroids?

Uterine fibroids are extremely common. In fact, many women have uterine fibroids at some point in life. Uterine fibroids in most women are usually too small to cause any problems, or even be noticed.

No one knows what causes uterine fibroids, but their growth seems to depend on estrogen, the female hormone. Uterine fibroids don’t develop until after puberty, and usually after age 30. Uterine fibroids tend to shrink or disappear after menopause, when estrogen levels fall.

Types of Uterine Fibroids

All uterine fibroids are similar in their makeup: All are made of abnormal uterine muscle cells growing in a tight bundle or mass.

Uterine fibroids are sometimes classified by where they grow in the uterus:

  • Myometrial (intramural) fibroids are in the muscular wall of the uterus.
  • Submucosal fibroids grow just under the interior surface of the uterus, and may protrude into the uterus.
  • Subserosal fibroids grow on the outside wall of the uterus.
  • Pedunculated fibroids usually grow outside of the uterus, attached to the uterus by a base or stalk.

Uterine fibroids can range in size, from microscopic to several inches across and weighing tens of pounds.

Symptoms of Uterine Fibroids

Most often, uterine fibroids cause no symptoms at all — so most women don’t realize they have them. When women do experience symptoms from uterine fibroids, they can include:

  • Prolonged menstrual periods (7 days or longer)
  • Heavy bleeding during periods
  • Bloating or fullness in the belly or pelvis
  • Pain in the lower belly or pelvis
  • Constipation
  • Pain with intercourse

Some experts believe that some uterine fibroids can occasionally interfere with fertility and pregnancy. Although it’s rare, a uterine fibroid projecting into the uterus might either block an embryo from implanting there, or cause problems with the pregnancy later.  

Diagnosis of Uterine Fibroids

Moderate and large-sized uterine fibroids are often felt by a doctor during a manual pelvic examination. Imaging tests are often done to confirm the presence of uterine fibroids.

Ultrasound

An ultrasound probe is inserted into the vagina or over the pelvis on the abdomen, and high-frequency sound waves reflect off the uterus and pelvic structures. The uterus and any uterine fibroids are displayed on a video screen.

Magnetic resonance imaging (pelvic MRI)

An MRI scanner uses a high-powered magnet and a computer to create highly detailed images of the uterus and other pelvic structures. Pelvic MRI can confirm the presence of uterine fibroids, if the diagnosis is unclear.

Uterine biopsy

Occasionally, a doctor may be concerned that a mass in the uterus is cancer, not a uterine fibroid. A small piece of tissue (biopsy) taken from the uterus can usually tell a fibroid from cancer. A uterine biopsy may be done through the vagina, or may require surgery.

Hysterosalpingogram

Dye is injected into the uterus through the vagina and cervix, and X-ray films show an outline of the uterus and fallopian tubes. Hysterosalpingogram is usually done in women with uterine fibroids who are trying to become pregnant.

Sonohysterogram

A water solution is injected into the uterus through the vagina and cervix, and an ultrasound is then done. Sonohysterogram may show uterine fibroids or other growths not visible on a traditional ultrasound.

Hysteroscopy

A tube with a lighted viewer on its tip (endoscope) is advanced into the uterus, and a video screen shows the uterus interior. Hysteroscopy can detect uterine fibroids projecting into the uterus, but cannot see any part of a fibroid in the uterus wall or outside the uterus.

Not all women will need extensive testing for uterine fibroids. In most women, a pelvic exam and ultrasound are sufficient to make the diagnosis of uterine fibroids. 

Treatment of Uterine Fibroids

Most uterine fibroids don’t need any treatment, because they don’t cause symptoms or problems. Uterine fibroids causing problems may be treated with non-surgical or surgical options.

Non-Surgical Treatment Options

Watchful waiting: A minority of fibroids will naturally shrink over time. Most uterine fibroids will either stay the same size or grow.

Oral contraceptives (birth control pills): These contain hormones (estrogen, progesterone, or a combination) that can help reduce heavy periods caused by uterine fibroids.

Lupron: This hormone treatment stops menstrual periods and shrinks uterine fibroids. Lupron is usually used as a temporary treatment before surgery.

Intrauterine device (IUD) with levonorgestrel: Mirena is an IUD that releases a hormone that reduces heavy periods.

Pain relievers: Motrin or Aleve can reduce the pain caused by uterine fibroids.

Iron: Heavy periods caused by uterine fibroids can lead to iron-deficiency anemia. Iron tablets can help the body replace the blood lost during menstruation.

Surgical Treatment Options

Myomectomy: Surgery to remove uterine fibroids while leaving the uterus in place. Myomectomy is often done for women wishing to have children. New uterine fibroids may grow, requiring a later procedure in up to a third of women after myomectomy.

Hysterectomy: Surgery to remove the entire uterus and all uterine fibroids. Hysterectomy cures uterine fibroids and prevents them from ever returning. Women with symptoms from uterine fibroids who don’t want a future pregnancy often undergo hysterectomy.

Surgeons perform myomectomy and hysterectomy through different techniques. These can determine time in the hospital, healing time, and scarring.

  • Open abdominal surgery: A surgeon makes a 5-inch to 7-inch incision either up and down or side to side across the belly. The fibroids (and/or the uterus) are removed through this incision.
  • Vaginal approach: The surgeon makes a cut in the vagina and removes the uterus through this incision. The incision is closed, leaving no visible scar on the abdominal wall.
  • Laparoscopy: Several small cuts are made in the belly, and a lighted camera and surgical tools are inserted through these incisions. In a single site laparoscopic procedure, just one small cut is made through the belly button. The surgeon operates from outside the body and removes the fibroids or fibroids and uterus through these small incisions or through a vaginal incision, viewing the operation on a video screen.
  • Robot-assisted laparoscopy: This procedure is similar to laparoscopy, but the surgeon controls a sophisticated robotic system of surgical tools from outside the body. Advanced technology allows the surgeon to use natural wrist movements and view the surgery on a three-dimensional screen.
  • A less invasive type of myomectomy uses a hysteroscope — the long, thin lighted tube mentioned above — to enter the uterus through the vagina and cervix and remove submucosal fibroids. Fibroids can then be removed by a tool inserted through the hysteroscope.

The vaginal approach, laparoscopy, and robot-assisted laparoscopy are minimally invasive procedures or MIPs. MIPs offer certain benefits over the more traditional open surgery approach. In general, a MIP allows for faster recovery, shorter hospital stays, and less pain and scarring than does an open abdominal surgery.

Uterine artery embolization (UAE): A procedure that cuts off blood flow to a uterine fibroid, causing it to shrink. UAE is not a surgical procedure. It is a minimally invasive procedure during which a thin tube — catheter — is inserted into an artery in the groin and guided using X-ray cameras to arteries that feed the uterus. Once it’s there, the doctor injects very small particles through the tube. The particles clog the blood vessels that feed the fibroid tumor. That causes them to shrink over time and alleviate symptoms.

Because it is a minimally invasive procedure, some women go home the same day. Most often, an overnight stay in the hospital is required. The procedure can cause cramping and pelvic pain that may last a few days. But typically, women can return to work and their normal activities after about one week. Not all women are candidates for this procedure.  Talk to your doctor about your best options.