What Are Fibroids?

Fibroids are tumors made up of muscle tissue. They grow in the wall of the uterus and are almost always noncancerous (benign). Uterine fibroids may grow as a single tumor or a clump of several tumors. The size of a fibroid varies from as small as an apple seed to as large as a grapefruit. 

Many people with fibroids do not experience symptoms. If you do have symptoms, you may also have accompanying cramps and heavy menstrual bleeding. The exact cause of fibroids is unknown but there are certain risk factors that can increase your risk of developing them.

It is estimated that up to 20% to 80% of people with uteruses develop fibroids by age 50. The good news: there are several treatment options available for fibroids, ranging from medication to surgery. Your exact treatment plan will depend on the severity of your fibroids and symptoms.

Types of Fibroids

There are different types of fibroids. Each type depends on what part of the uterus they develop in. The various types of fibroids include:

  • Submucosal fibroids: Grow into the uterine cavity (inside the uterus)
  • Intramural fibroids: Grow within the wall of the uterus
  • Subserosal fibroids: Grow near or on the outside of the uterus
  • Pedunculated fibroids: Grow on stalks that come out of the uterus
Schematic drawing of various types of uterine fibroids: subserosal, intramural, submucosal, and pedunculated fibroids. Female reproductive system (internal sex organs). uterus with broad ligament on the white background. Human anatomy

ttsz / Getty Images

Symptoms

The majority of people with fibroids do not experience symptoms. However, it's estimated that about 30% of people with fibroids have severe symptoms that interfere with their daily lives. 

Fibroid symptoms depend on how big the fibroids are and where they grow. If you're having symptoms because of your fibroids, you might be experiencing:

Causes

Fibroids occur when muscular tumors grow in or on the uterus. The exact cause of fibroids is unknown but researchers believe there are hormonal and genetic factors that may lead to their development.

The hormones estrogen and progesterone can affect the development and size of your fibroids. Fibroids tend to grow rapidly during pregnancy when hormone levels rise. They shrink with anti-hormone medications that lower the level of hormones in your body. Your fibroids may also shrink after menopause when hormone levels naturally decrease. 

Some research also suggests that fibroids may develop genetically and run in families. Having the following genetic mutations may raise your risk of fibroids: MED12, HMGA2, COL4A5/COL4A6, and FH genes.

Risk Factors

While the exact cause of fibroids is unknown, there are certain factors that can raise your risk. These risk factors include:

  • Age: Fibroids are more common as you age and then usually shrink after menopause.
  • Family history: If your parent or sibling had fibroids, your risk is three times higher than those who don't have a family history of fibroids.
  • Obesity: The risk of fibroids is two to three times greater if you are obese.
  • Dietary habits: Eating large amounts of red meat and ham raises the risk of fibroids. Some early studies suggest that eating green vegetables may reduce your risk of developing fibroids.

Diagnosis

A gynecologist, or a medical doctor who specializes in treating conditions of the female reproductive system, can check if you have fibroids and provide you with a proper diagnosis. In addition to taking your medical history, your healthcare provider may perform the following diagnostic tests to confirm the presence of fibroids:

  • Pelvic exam: Your provider will check your uterus, ovaries, and vagina. It is possible to feel fibroids during a pelvic exam.
  • Ultrasound: This test uses sound waves to produce pictures. A provider can perform an ultrasound on the abdomen and inside the vagina.
  • Magnetic resonance imaging (MRI): An MRI uses magnets and radio waves to produce images of the uterus and detect fibroids. 
  • X-ray: This test uses radiation to visualize the uterus and produce images.
  • Computed tomography (CT) scan: A CT scan uses X-ray pictures from different angles to detect fibroids. 
  • Hysterosalpingogram (HSG): This test involves injecting a contrast dye into the uterus and taking X-ray pictures of the uterus. 
  • Sonohysterogram: During this test, your healthcare provider injects water into the uterus and can create images via ultrasound.
  • Laparoscopy: This minor surgery uses a long, thin scope that is inserted into the uterus through tiny cuts made near the belly button. Your surgeon can then check for the presence of fibroids.
  • Hysteroscopy: This exam uses a long, thin scope with a light attached to it and passes the scope through the vagina and cervix into the uterus to assess fibroids. Keep in mind: this procedure does not make cuts or incisions into your skin.

Treatment

Many cases of fibroids do not require treatment. If you have fibroids that are small and do not cause symptoms, your healthcare provider will likely recommend monitoring them over time to check for any changes in size or the development of symptoms.

If you are experiencing pain, heavy bleeding, or other symptoms from fibroids, your provider will share treatment options with you. Treatment options for fibroids include medications and surgery. 

Medications that can help treat fibroids include: 

  • Over-the-counter (OTC) pain medications: Advil (ibuprofen) or Tylenol (acetaminophen) can help with pain relief
  • Vitamin supplements: Taking an iron or vitamin D supplement can reduce heavy menstrual bleeding
  • Low-dose birth control: Birth control pills or injections can regulate your hormone levels and improve fibroid symptoms

If you are experiencing severe symptoms that do not improve with medications, surgery may be the next step. Possible surgical treatments for fibroids include:

  • Myomectomy: Removes fibroids without removing the healthy tissue of the uterus. People who have this surgery can still become pregnant. 
  • Hysterectomy: Takes out the entire uterus and is the only way to cure uterine fibroids. People who have this surgery will not be able to become pregnant after the procedure. This surgery is only used when your fibroids are very large or cause uncontrolled bleeding.
  • Endometrial ablation: Gets rid of the lining of the uterus by destroying it with a laser, wire loops, boiling water, electric current, microwaves, or freezing. It is used to relieve heavy menstrual bleeding and should be considered an option only if you do not plan on becoming pregnant in the future. 
  • Myolysis: Destroys fibroids by electrical current or freezing via a needle
  • Uterine fibroid embolization (UFE) or uterine artery embolization (UAE): Helps shrink fibroids by placing a thin tube in the fibroid's blood vessels and injecting gel particles to block the blood supply.
  • Radiofrequency ablation: Uses heat to destroy fibroid tissue and shrink fibroids without affecting the surrounding tissue.

How to Prevent Fibroids 

Because the exact cause of fibroids is unknown, there is no proven way to prevent them. Most people with fibroids do not experience symptoms. In fact, people may not even know they have fibroids unless a healthcare provider notices them during a routine pelvic exam.

While fibroids can't be prevented, it is sometimes possible to lower your risk of fibroids. Some preventative strategies include:

  • Maintaining a healthy weight that is right for you
  • Taking birth control
  • Eating less red meat

Keep in mind: These strategies cannot always be controlled and may not be right for you. That's why it's important to work with your healthcare provider to lower your risk of fibroids.

Complications 

Having uterine fibroids may raise your risk of other conditions or complications. While most fibroids are benign (non-cancerous), about 1 in 1,000 fibroids are cancerous. A cancerous fibroid is known as a leiomyosarcoma. Uterine fibroids may also affect your fertility and reproductive health. Fibroids usually do not cause infertility but if they are especially large, they can lower your chances of becoming pregnant. 

Most people with fibroids can have normal pregnancies, but fibroids may increase your risk of pregnancy complications. Research shows that people with fibroids have a greater risk of having a cesarean section (C-section) than those without fibroids. Fibroids may also raise the risk of placental abruption, an emergency that occurs when the placenta breaks away from the wall of the uterus. This cuts off the oxygen supply to your baby and needs to be treated immediately.

When to Contact Your Healthcare Provider

Fibroids can cause serious health problems such as uncontrolled bleeding. Call your healthcare provider right away if you experience:

  • Excessively heavy period bleeding
  • Regular bleeding between periods
  • Significant pain during mensturation
  • Difficulty urinating 

Living With Fibroids  

Fibroids are relatively common, and most do not require treatment. That means that many people are likely to be living with fibroids. If your fibroids do not cause symptoms, you generally do not have to take any special steps to live with them. 

If you experience symptoms around your period, such as pelvic pain or heavy bleeding, plan ahead for your menstrual cycle. If you’re able to slow down your schedule around your period, this could be a time to get extra rest. Plan to use any medications and other treatment strategies that help improve your symptoms. 

If you’re finding that your fibroid symptoms are interfering with your daily life, it's best to talk with your healthcare provider about how to better manage your fibroids and ways to improve your overall quality of life.

Frequently Asked Questions

  • Do fibroids make you gain weight?

    Fibroids may cause weight gain if they are especially large. For example, large fibroids can grow as big as a grapefruit and even make a person appear pregnant. 

  • Can fibroids turn cancerous?

    Almost all fibroids are noncancerous. It’s estimated that about 1 in 1,000 fibroids are cancerous. Benign fibroids do not turn into cancerous ones. 

  • Is fibroid surgery painful?

    As with any surgery, your medical team will provide anesthesia and pain control during fibroid surgery. The procedure itself should not be painful. However, you may experience pain and soreness while you heal from surgery. 

  • Do fibroids need to be removed?

    Most fibroids do not cause symptoms and do not need to be removed. Fibroids only need to be removed if they cause significant symptoms and interfere with your daily life.

Was this page helpful?
5 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Office on Women’s Health. Uterine fibroids.

  2. MedlinePlus. Uterine fibroids.

  3. Giuliani E, As-Sanie S, Marsh EE. Epidemiology and management of uterine fibroids. Int J Gynaecol Obstet. 2020;149(1):3-9. doi:10.1002/ijgo.13102

  4. National Institute of Child Health and Human Development. Uterine fibroids.

  5. De La Cruz MS, Buchanan EM. Uterine fibroids: Diagnosis and treatment. Am Fam Physician. 2017;95(2):100-107.

Related Articles