What Are Uterine Fibroids?
A uterine fibroid is the most common benign (not cancerous) tumor of a woman's uterus (womb). It is also called uterina myoma. Fibroids are tumors of the smooth muscle found in the wall of the uterus. They can develop within the uterine wall itself or attach to it. They may grow as a single tumor or in clusters. Uterine fibroids can cause excessive menstrual bleeding, pelvic pain, and frequent urination.
- These growths occur in up to 50% of all women and are one leading cause of hysterectomy (removal of the uterus) in the United States. An estimated 600,000 hysterectomies are performed in the US annually, and at least one-third of these procedures are for fibroids. Medications and newer, less invasive surgical treatments are now available to help control the growth of fibroids.
- Fibroids start in the muscle tissues of the uterus. They can grow into the uterine cavity (submucosal), into the thickness of the uterine wall (intramuscular), or on the surface of the uterus (subsersoal) into the abdominal cavity. Some may occur as pedunculated masses (fibroids growing on a stalk off of the uterus).
- Although these tumors are called fibroids, this term is misleading because they consist of muscle tissue, not fibrous tissue. The medical term for a fibroid is leiomyoma, a type of myoma or mesenchymal tumor.
Picture of uterine fibroids
What Causes Uterine Fibroids?
The exact reasons why some women develop fibroids are unknown. Fibroids tend to run in families, and affected women often have a family history of fibroids. Women of African descent are two to three times more likely to develop fibroids than women of other races.
Fibroids grow in response to stimulation by the hormone estrogen, produced naturally in the body. These growths can show up as early as age 20, but tend to shrink after menopause when the body stops producing large amounts of estrogen.
Fibroids can be tiny and cause no problems, or they also can grow to weigh several pounds. Fibroids generally tend to grow slowly.
The following factors have been associated with the presence of fibroids:
- Being overweight, obesity
- Never having given birth to a child (called nulliparity)
- Onset of the menstrual period prior to age 10
- African American heritage (occurring 3-9 times more often than in Caucasian women)
Endometriosis occurs deep inside the uterus.
What Are the Symptoms of Uterine Fibroids?
Most fibroids, even large ones, produce no symptoms. These masses are often found during a regular pelvic examination.
When women do experience symptoms, the most common are the following:
- an increase in menstrual bleeding, known as menorrhagia, sometimes with blood clots;
- pressure on the bladder, which may cause frequent urination and a sense of urgency to urinate and, rarely, the inability to urinate;
- pressure on the rectum, resulting in constipation;
- pelvic pressure, "feeling full" in the lower abdomen, lower abdominal pain;
- increase in size around the waist and change in abdominal contour (some women may need to increase their clothing size but not because of a significant weight gain);
- infertility, which is defined as an inability to become pregnant after 1 year of attempting to get pregnant; and/or
- a pelvic mass discovered by a health care practitioner during a physical examination.
When Should I Call the Doctor About Uterine Fibroids?
If a woman has any questions about her uterine health, seek medical assistance as soon as possible. If a woman has any of the following, she should notify her health care practitioner:
If a woman has any of the following signs or symptoms she should contact a health care practitioner immediately or go to a hospital's emergency department.
- Menstrual bleeding soaking through more than 3 pads per hour
- Severe or prolonged pelvic or abdominal pain
- Dizziness, lightheadedness, shortness of breath, or chest pain associated with vaginal bleeding
- Vaginal bleeding associated with pregnancy or possible pregnancy
How Are Uterine Fibroids Diagnosed?
A woman's health care practitioner will discuss her medical history and conduct a physical examination that includes a pelvic exam. Often a doctor can feel an irregularly shaped uterus when fibroids are present.
If further studies are indicated, the doctor may choose one of the following tests to help decide if the patient has fibroids and to exclude other and potentially more serious causes of ongoing symptoms:
- An abdominal, transvaginal or pelvic ultrasound can help identify the number, size, and shape of most fibroids. These test use sound waves to give doctors an image of the pelvic area. A wand is passed over the abdomen (abdominal ultrasound) for one type of view. Another probe (or wand) may be inserted into the vagina to obtain additional views (pelvic or transvaginal ultrasound).
- An endometrial biopsy is performed by taking a tissue sample from the uterus. A small instrument is passed through the cervical opening to "grab" small samples of tissue inside the uterus. It can be performed at a doctor's office.
- A hysteroscopy looks inside the uterus by passing a small fiberoptic camera through the opening of the cervix.
- Hysterosalpingography involves injection of dye into the uterus and Fallopian tubes, which is then X-rayed to identify the anatomy of these structures.
- Laparoscopy is a surgical procedure. The surgeon will insert a small fiberoptic camera into the abdomen through small abdominal incisions to look directly at internal organs.
What Is the Treatment for Uterine Fibroids?
Treatment for fibroids depends on the symptoms, the size and location of the fibroids, age (how close the person is to menopause), the patient's desire to have children, and the patient's general health.
Are There Home Remedies for Uterine Fibroids?
No specific self-care is available for fibroids. However, if a woman has abnormal or heavy menstrual bleeding, she should keep a diary of her menstrual cycle in order to provide the information to her health care practitioner.
What Is the Medical Treatment for Uterine Fibroids?
In most cases, treatment is not necessary, particularly if the woman has no symptoms, has small tumors, or has gone through menopause. Abnormal vaginal bleeding caused by fibroids may require surgical scraping of the uterine cavity in a procedure known as a dilation and curettage (D&C). If no malignancy (cancer) is found, this bleeding often can be controlled by hormonal medications. The following treatment options should be discussed with a health care practitioner.
- The gynecologist may follow the size and growth of the fibroids over time to make sure no indicators of cancer are present.
- If the person does not have symptoms such as vaginal bleeding or pelvic pain, and if the fibroid is not growing rapidly, no treatment may be needed.
- Some patient's may, however, require more frequent pelvic exams, such as every 6 months, to check on changes with the fibroid(s).
Pelvic Pain: What's Causing Your Pelvic Pain?
What Are the Medications For Uterine Fibroids?
Patients may be given nonsteroidal anti-inflammatory drugs, oral contraceptives (birth control pills), gonadotropin releasing hormone agonists, or RU-486.
- Nonsteroidal anti-inflammatory agents, such as ibuprofen (Advil is one example), have been shown to relieve pelvic pain associated with fibroids.
- Oral contraceptive pills are also commonly used in women with fibroids. They often decrease perceived menstrual blood flow and help with pelvic pain.
- Gonadotropin releasing hormone (GnRH) agonists are medications that act on the pituitary gland to decrease estrogen produced by the body. A decrease in estrogen causes fibroids to decrease in size. This type of medication often is used prior to surgery to shrink the fibroid, to decrease the amount of blood loss during surgery, or to improve preoperative blood count. The size of the fibroid can be reduced by 50% in three months with of this type of therapy. But fibroids can regrow once treatment is stopped. Long-term therapy with these medications is limited by the side effects of low estrogen (much like menopause), which include decreased bone density, osteoporosis, hot flashes, and vaginal dryness.
- The antihormonal drug RU-486 (mifepristone) has also been shown to reduce fibroid size by about half. This drug has also been shown to reduce pelvic pain, bladder pressure, and lower back pain. Low doses of this drug may reduce the size of fibroids in preparation for surgery to remove them. It may also help some patients avoid surgery entirely by shrinking the fibroids and the problems they are causing. Side effects related to low estrogen, seen with GnRH analogs, may be less common. RU-486 can induce miscarriage, so this medication should be used with caution if a woman is trying to conceive.
- The drug danazol (Danocrine) has been used to reduce bleeding in women with fibroids, since this drug causes menstruation to cease, but it does not shrink the size of fibroids. Danazol is an androgenic (male) hormonal drug that can cause serious side effects including weight gain, muscle cramps, decreased breast size, acne, hirsutism (inappropriate hair growth), oily skin, mood changes, depression, decreased high density lipoprotein (HDL or 'good cholesterol') levels, and increased liver enzyme levels.
- Another new drug may be useful in treating some uterine fibroids. It is a progesterone receptor modulator named EllaOne. It is used as an emergency contraception drug, but was found to shrink fibroids and reduce bleeding associate with fibroids.
What Is the Surgery for Uterine Fibroids?
Surgery options for treatment have both risks and benefits. Be sure to discuss these risks and benefits with the doctor. Some treatment options may not be right for a woman because of the characteristics of the fibroids or other health factors.
- Myomectomy is the surgical removal of the fibroids only. This can be accomplished through hysteroscopy, laparoscopy, or, less frequently, an open procedure (an incision in the abdomen). The surgical approach depends on the size and location of the fibroid. Pretreatment with GnRH analogs has been shown to decrease blood loss and operative time in women undergoing myomectomy. Myomectomy has also been shown to have a decreased likelihood of injury to the bowel, bladder, or ureter than hysterectomy. The uterus is left intact in this type of procedure, and the patient may be able to become pregnant.
- Hysterectomy is the surgical removal of the uterus (and fibroids). It is the most commonly performed surgical procedure in the treatment of fibroids and is considered a cure. Depending on the size of the fibroid, hysterectomy can be performed with incisions through the vagina or abdomen. In some cases the procedure may be performed using laparoscopy. Use of GnRH agonists can reduce the size of the fibroid to allow less invasive surgical techniques. In past experience, less blood loss has occurred using hysterectomy than myomectomy. Hysterectomy with removal of the Fallopian tubes and ovaries (called a salpingo-oophorectomy) may be indicated if there is suspicion of cancer or if ovarian masses are present.
- Uterine artery embolization, or clotting of the arterial blood supply to the fibroid, is an innovative approach that has shown promising results. This procedure is done by inserting a catheter (small tube) into an artery of the leg (the femoral artery), using special X-ray video to trace the arterial blood supply to the uterus, then clotting the artery with tiny plastic or gelatin sponge particles the size of grains of sand. This material blocks blood flow to the fibroid and shrinks it. This method may prove to be a good option for women if other methods have not worked, she does not want surgery, or may not be good candidates for surgery. A specialist known as an interventional radiologist performs this procedure.
- A newer procedure has also shown promise: magnetic resonance guided focused ultrasound. In this procedure, MRI is used to guide an ultrasound beam that heats the fibroids and helps to heat and destroy small areas of fibroid tissue.
Is Other Therapy Available for Uterine Fibroids?
Constipation and hemorrhoids are other symptoms caused by the pressure of growing fibroids. Some women can avoid these problems and relieve symptoms by eating more whole grains, bran, and fruit and by drinking plenty of water. Natural laxative products also may help; a woman should discuss these symptoms and treatments with her health care practitioner.
How Do I Prevent Uterine Fibroids?
- Women should avoid weight gain after age 18 and maintain a normal body weight compared to height. Body weight tends to increase estrogen production, thus aggravating fibroid growth.
- Exercise can help women control weight and additionally decrease hormone production that stimulates fibroid growth.
- Tobacco use has not been proven to be linked to an increase in fibroids. But quitting smoking will improve general health and well being of women that have fibroids.
- Routine health visits with a health care practitioner may allow for early detection of fibroids.
What Is the Follow-up for Uterine Fibroids?
All patients should follow their health care practitioner's instructions. A health care practitioner may choose to do more frequent pelvic exams, such as every six months, to determine whether there is growth of a fibroid.
Patients should educate themselves about treatment options. Patients may need to make a choice depending on the progression of their treatment and their fibroid symptoms; their health care providers can help them to get information about any treatment options.
What Is the Prognosis for Uterine Fibroids?
- Treatment success and future outcome depend on the severity of the fibroid or fibroids prior to treatment and the chosen treatment.
- Fibroids may affect fertility, but this depends on the size and location of the fibroids.
- Many women with fibroids are older than 35 years. This and other factors such as decreased egg quality and decreased ovulation contribute to their inability to become pregnant.
- Fibroids rarely turn into cancer. This is more likely to occur in women after menopause.
- The most common warning sign of cancer is a rapidly growing tumor that requires surgery.
Reviewed on 7/10/2019
Medically reviewed by Steven Nelson, MD; Board Certified Obstetrics and Gynecology
eMedicine.com. Leiomyoma, uterus.
Parker, WH. Uterine Myomas: Management. Fertil Steril. 2007 Aug;88(2):255-71. Epub 2007 Jul 20.