Uterine fibroids are tumors that grow in a woman's womb (uterus). These growths are not cancer (benign).
Leiomyoma; Fibromyoma; Myoma; Fibroids
Uterine fibroids are common. As many as 1 in 5 women may have fibroids during their childbearing years. Half of all women have fibroids by age 50.
Fibroids are rare in women under age 20. They are more common in African-Americans than Caucasians.
No one knows exactly what causes fibroids. They are thought to be caused by:
Hormones in the body
Genes (may run in families)
Fibroids can be so tiny that you need a microscope to see them. They can also grow very large. They may fill the entire uterus and may weigh several pounds. Although it is possible for just one fibroid to develop, usually there are more than one.
Fibroids can grow:
In the muscle wall of the uterus (myometrial)
Just under the surface of the uterine lining (submucosal)
Just under the outside lining of the uterus (subserosal)
On a long stalk on the outside the uterus or inside the uterus (pedunculated)
Common symptoms of uterine fibroids are:
Bleeding between periods
Heavy bleeding during your period, sometimes with blood clots
Periods that may last longer than normal
Needing to urinate more often
Pelvic cramping or pain with periods
Feeling fullness or pressure in your lower belly
Pain during intercourse
Often, you can have fibroids and not have any symptoms. Your health care provider may find them during a physical exam or other test. Fibroids often shrink and cause no symptoms in women who have gone through menopause. A recent study also showed that some small fibroids shrink in premenopausal women.
Exams and Tests
Your health care provider will perform a pelvic exam. This may show that you have a change in the shape of your womb.
Fibroids aren't always easy to diagnose. Being obese may make fibroids harder to detect. Your doctor may do these tests to look for fibroids:
Ultrasound uses sound waves to create a picture of the uterus
MRI uses powerful magnets and radio waves to create a picture
Saline infusion sonogram (hysterosonography): Saline is injected into the uterus to make it easier to see the uterus using ultrasound
Hysteroscopy uses a long, thin tube inserted into through the vagina and into the uterus to examine the inside of the uterus
If you have unusual bleeding, your doctor may do one of these procedures:
A small piece of the lining of the uterus is removed and checked for cancer (endometrial biopsy)
The doctor inserts a small tube through a small cut in your belly to look inside your pelvis (laparoscopy)
What type of treatment you have depends on:
Your general health
Type of fibroids
If you are pregnant
If you want children in the future
Treatment for the symptoms of fibroids may include:
Birth control pills to help control heavy periods
Intrauterine devices (IUDs) that release hormones to help reduce heavy bleeding and pain
Iron supplements to prevent or treat anemia due to heavy periods
Pain relievers such as ibuprofen or naprosyn for cramps or pain
Hormone therapy shots to help shrink fibroids (done only for a short time)
Watchful waiting: You may have pelvic exams or ultrasounds every once in a while to check the fibroid's growth
Surgery and procedures used to treat fibroids include:
Hysteroscopy. This procedure can remove fibroids growing inside the uterus.
Uterine artery embolization.This procedure stops the blood supply to the fibroid, causing it to shrink and die. This may be a good option if you want to have children in the future.
Myomectomy. This surgery removes the fibroids from the uterus. This also may be a good choice if you want to have children. It won't prevent fibroids from growing again.
Hysterectomy. This surgery removes the uterus completely. It may be an option if you don't want children, medicines do not work, and you cannot have any other procedures.
If you have fibroids without symptoms, you may not need treatment.
If you have fibroids, they may grow if you become pregnant. This is due to the increased blood flow and higher estrogen levels. The fibroids usually return to their original size after your baby is born.
Complications of fibroids include:
Severe pain or very heavy bleeding that needs emergency surgery
Twisting of the fibroid. This can causes blocked blood vessels that feed the tumor. You may need surgery if this happens.
Anemia (not having enough red blood cells) from heavy bleeding
Urinary tract infections: If the fibroid presses on the bladder, it can make it hard to empty your bladder completely.
Infertility, in rare cases.
If you are pregnant, there's a small risk that fibroids also may cause complications:
You may deliver your baby early because there is not enough room in your womb.
If the fibroid blocks the birth canal or puts the baby in a dangerous position, you may need a c-section.
You may have heavy bleeding right after giving birth.
When to Contact a Medical Professional
Call your health care provider if you have:
Heavy bleeding, increased cramping, or bleeding between periods
Fullness or heaviness in your lower belly area
American College of Obstetricians and Gynecologists. ACOG practice bulletin. Alternatives to hysterectomy in the management of leiomyomas. Obstet Gynecol. 2008;112:387-400.
Borkan J. Uterine Fibroids. In: Ferri F.: Ferri's Clinical Advisor. 1st ed. Philadelphia, Pa: Mosby Elsevier; 2014 Section 1 U.
Rodriguez MI, Warden M, Darney PD. Intrauterine progestins, progesterone antagonists, and receptor modulators: a review of gynecologic applications. Am J Obstet Gynecol. 2010 May;202(5):420-8. Epub 2009 Dec 23. Review.
Moss J, Cooper K, Khaund A, et al. Randomised comparison of uterine artery embolisation (UAE) with surgical treatment in patients with symptomatic uterine fibroids (REST trial): 5-year results. BJOG. 2011 Jul;118(8):936-944.
Peddada SD, Laughlin SK, Miner K, et al. Growth of uterine leiomyomata among premenopausal black and white women. Proc Natl Acad Sci USA. 2008 Dec 16;105(50):19887-92. Epub 2008 Dec 1.
Van Voorhis B. A 41-year-old woman with menorrhagia, anemia, and fibroids: review of treatment of uterine fibroids. JAMA. 2009;301:82-93.
Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.