What are uterine fibroids?
Uterine fibroids (also called leiomyomas) are growths made up of the muscle and connective tissue from the wall of the uterus. These growths are usually not cancerous (benign). Your uterus is an upside down pear-shaped organ in your pelvis. The normal size of your uterus is similar to a lemon. It’s also called the womb and it’s the place where a baby grows and develops during pregnancy.
Fibroids can grow as a single nodule (one growth) or in a cluster. Fibroid clusters can range in size from 1 mm to more than 20 cm (8 inches) in diameter or even larger. For comparison, they can get as large as the size of a watermelon. These growths can develop within the wall of the uterus, inside the main cavity of the organ or even on the outer surface. Fibroids can vary in size, number and location within and on your uterus.
You may experience a variety of symptoms with uterine fibroids and these may not be the same symptoms that another woman with fibroids will experience. Because of how unique fibroids can be, your treatment plan will depend on your individual case.
Are fibroids common?
Fibroids are actually a very common type of growth in your pelvis. Approximately 40 to 80% of people have fibroids. However, many people don’t experience any symptoms from their fibroids, so they don’t realize they have fibroids. This can happen when you have small fibroids — called asymptomatic because they don’t cause you to feel anything unusual.
Who is at risk for uterine fibroids?
There are several risk factors that can play a role in your chances of developing fibroids. These can include:
- Obesity and a higher body weight (more than 20% over the weight that's considered healthy for you).
- Family history of fibroids.
- Not having children.
- Early onset of menstruation (getting your period at a young age).
- Late age for menopause.
Where do fibroids grow?
There are several places both inside and outside of your uterus where fibroids can grow. The location and size of your fibroids is important for your treatment. Where your fibroids are growing, how big they are and how many of them you have will determine which type of treatment will work best for you or if treatment is even necessary.
There are different names given for the places your fibroids are located in and on the uterus. These names describe not only where the fibroid is, but how it’s attached. Specific locations where you can have uterine fibroids include:
- Submucosal fibroids: In this case, the fibroids are growing inside the uterine space (cavity) where a baby grows during pregnancy. Think of the growths extending down into the empty space in the middle of the uterus.
- Intramural fibroids: These fibroids are embedded into the wall of the uterus itself. Picture the sides of the uterus like walls of a house. The fibroids are growing inside this muscular wall.
- Subserosal fibroids: Located on the outside of the uterus this time, these fibroids are connected closely to the outside wall of the uterus.
- Pedunculated fibroids: The least common type, these fibroids are also located on the outside of the uterus. However, pedunculated fibroids are connected to the uterus with a thin stem. They’re often described as mushroom-like because they have a stalk and then a much wider top.
What do fibroids look like?
Fibroids are typically rounded growths that can look like nodules of smooth muscle tissue. In some cases, they can be attached with a thin stem, giving them a mushroom-like appearance.
Are fibroids cancer?
It’s extremely rare for a fibroid to go through changes that transform it into a cancerous or a malignant tumor. In fact, one out of 350 people with fibroids will develop malignancy. There’s no test that’s 100% predictive in detecting rare fibroid-related cancers. However, people who have rapid growth of uterine fibroids, or fibroids that grow during menopause, should be evaluated immediately.
Symptoms and Causes
What causes uterine fibroids?
The causes of fibroids are not known. Most fibroids happen in people of reproductive age. They typically aren’t seen in young people who haven’t had their first period yet.
What are the symptoms of uterine fibroids?
Most fibroids do not cause any symptoms and don’t require treatment other than regular observation by your healthcare provider. These are typically small fibroids. When you don’t experience symptoms, it’s called an asymptomatic fibroid. Larger fibroids can cause you to experience a variety of symptoms, including:
- Excessive or painful bleeding during your period (menstruation).
- Bleeding between your periods.
- A feeling of fullness in your lower abdomen/bloating.
- Frequent urination (this can happen when a fibroid puts pressure on your bladder).
- Pain during sex.
- Low back pain.
- Chronic vaginal discharge.
- Inability to urinate or completely empty your bladder.
- Increased abdominal distention (enlargement), causing your abdomen to look pregnant.
The symptoms of uterine fibroids usually stabilize or go away after you’ve gone through menopause because hormone levels decline within your body.
What does uterine fibroid pain feel like?
There are a variety of feelings you might experience if you have fibroids. If you have small fibroids, you may feel nothing at all and not even notice they’re there. For larger fibroids, however, you can experience discomforts and even pains related to the condition. Fibroids can cause you to feel back pain, severe menstrual cramps, sharp stabbing pains in your abdomen and even pain during sex.
Can fibroids change over time?
Fibroids can actually shrink or grow over time. They can change size suddenly or steadily over a long period of time. This can happen for a variety of reasons, but in most cases this change in fibroid size is linked to the amount of hormones in your body. When you have high levels of hormones in your body, fibroids can get bigger. This can happen at specific times in your life, like during pregnancy. Your body releases high levels of hormones during pregnancy to support the growth of your baby. This surge of hormones also causes the fibroid to grow. If you know you have fibroids before a pregnancy, talk to your healthcare provider. You may need to be monitored to see how the fibroid grows throughout the pregnancy. Fibroids can also shrink when your hormone levels drop. This is common after menopause. Once a woman has passed through menopause, the amount of hormones in her body is much lower. This can cause the fibroids to shrink in size. Often, your symptoms can also get better after menopause.
Can fibroids cause anemia?
Anemia is a condition that happens when your body doesn’t have enough healthy red blood cells to carry oxygen to your organs. It can make you feel tired and weak. Some people may develop intense cravings for ice, starch or dirt. This is called pica and is associated with anemia. Anemia can happen to people who have frequent or extremely heavy periods. Fibroids can cause your periods to be very heavy or for you to even bleed between periods. Some treatments like oral iron pills — or if you're significantly anemic, an iron infusion (by IV) — can improve your anemia. Talk to your healthcare provider if you are experiencing symptoms of anemia while you have fibroids.
Diagnosis and Tests
How are uterine fibroids diagnosed?
In many cases, fibroids are first discovered during a regular exam with your health provider. They can be felt during a pelvic exam and can be found during a gynecologic exam or during prenatal care. Quite often your description of heavy bleeding and other related symptoms may alert your healthcare provider to consider fibroids as a part of the diagnosis. There are several tests that can be done to confirm fibroids and determine their size and location. These tests can include:
- Ultrasonography: This non-invasive imaging test creates a picture of your internal organs with sound waves. Depending on the size of the uterus, the ultrasound may be performed by the transvaginal or transabdominal route.
- Magnetic resonance imaging (MRI): This test creates detailed images of your internal organs by using magnets and radio waves.
- Computed tomography (CT): A CT scan uses X-ray images to make a detailed image of your internal organs from several angles.
- Hysteroscopy: During a hysteroscopy, your provider will use a device called a scope (a thin, flexible tube with a camera on the end) to look at fibroids inside your uterus. The scope is passed through your vagina and cervix and then moved into your uterus.
- Hysterosalpingography (HSG): This a detailed X-ray where a contrast material is injected first and then X-rays of the uterus are taken. This is more often used in people who are also undergoing infertility evaluation.
- Sonohysterography: In this imaging test, a small catheter is placed transvaginally and saline is injected via the catheter into the uterine cavity. This extra fluid helps to create a clearer image of your uterus than you would see during a standard ultrasound.
- Laparoscopy: During this test, your provider will make a small cut (incision) in your lower abdomen. A thin and flexible tube with a camera on the end will be inserted to look closely at your internal organs.
Management and Treatment
How are uterine fibroids treated?
Treatment for uterine fibroids can vary depending on the size, number and location of the fibroids, as well as what symptoms they’re causing. If you aren’t experiencing any symptoms from your fibroids, you may not need treatment. Small fibroids can often be left alone. Some people never experience any symptoms or have any problems associated with fibroids. Your fibroids will be monitored closely over time, but there’s no need to take immediate action. Periodic pelvic exams and ultrasound may be recommend by your healthcare provider depending on the size or symptoms of your fibroid.If you are experiencing symptoms from your fibroids — including anemia from the excess bleeding, moderate to severe pain, infertility issues or urinary tract and bowel problems — treatment is usually needed to help. Your treatment plan will depend on a few factors, including:
- How many fibroids you have.
- The size of your fibroids.
- Where your fibroids are located.
- What symptoms you are experiencing related to the fibroids.
- Your desire for pregnancy.
- Your desire for uterine preservation.
The best treatment option for you will also depend on your future fertility goals. If you want to have children in the future, some treatment options may not be an option for you. Talk to your healthcare provider about your thoughts on fertility and your goals for the future when discussing treatment options. Treatment options for uterine fibroids can include:
- Over-the-counter (OTC) pain medications: These medications can be used to manage discomforts and pain caused by the fibroids. OTC medications include acetaminophen and ibuprofen.
- Iron supplements: If you have anemia from the excess bleeding, your provider may also suggest you take an iron supplement.
- Birth control: Birth control can also be used to help with symptoms of fibroids — specifically heavy bleeding during and between periods and menstrual cramps. Birth control can be used to help control heavy menstrual bleeding. There are a variety of birth control options you can use, including oral contraceptive pills, intravaginal contraception, injections and intrauterine devices (IUDs).
- Gonadotropin-releasing hormone (GnRH) agonists: These medications can be taken via a nasal spray or injection and they work by shrinking your fibroids. They’re sometimes used to shrink a fibroid before surgery, making it easier to remove the fibroid. However, these medications are temporary and if you stop taking them, the fibroids can grow back.
- Oral therapies: Elagolix is a new oral therapy indicated for the management of heavy uterine bleeding in people who haven't experienced menopause with symptomatic uterine fibroids. It can be used up to 24 months. Talk to your doctor for pros and cons of this therapy. Another oral therapy, Tranexamic acid, is an antifibrinolytic oral drug that’s indicated for the treatment of cyclic heavy menstrual bleeding in people with uterine fibroids. Your doctor will monitor you during this therapy.
It’s important to talk to your healthcare provider about any medication you take. Always consult your provider before starting a new medication to discuss any possible complications.
There are several factors to consider when talking about the different types of surgery for fibroid removal. Not only can the size, location and number of fibroids influence the type of surgery, but your wishes for future pregnancies can also be an important factor when developing a treatment plan. Some surgical options preserve the uterus and allow you to become pregnant in the future, while other options can either damage or remove the uterus.
Myomectomy is a procedure that allows your provider to remove the fibroids without damaging the uterus. There are several types of myomectomy. The type of procedure that may work best for you will depend on where your fibroids are located, how big they are and the number of fibroids. The types of myomectomy procedure to remove fibroids can include:
- Hysteroscopy: This procedure is done by inserting a scope (a thin, flexible tube-like tool) through the vagina and cervix and into the uterus. No incisions are made during this procedure. During the procedure, you provider will use the scope to cut away the fibroids. Your provider will then remove the fibroids.
- Laparoscopy: In this procedure, your provider will use a scope to remove the fibroids. Unlike the hysteroscopy, this procedure involves placing a few small incisions in your abdomen. This is how the scope will enter and exist your body. This procedure can also be accomplished with the assistance of a robot.
- Laparotomy: During this procedure, an incision is made in your abdomen and the fibroids are removed through this one larger cut.
If you aren’t planning future pregnancies, there are additional surgical options your healthcare provider may recommend. These options are not recommended if pregnancy is desired and there are surgical approaches that remove the uterus. These surgeries can be very effective, but they typically prevent future pregnancies. Surgeries to remove fibroids can include:
- Hysterectomy: During this surgery, your uterus is removed. A hysterectomy is the only way to cure fibroids. By removing your uterus completely, the fibroids can’t come back and your symptoms should go away. If your uterus alone is removed — the ovaries are left in place — you will not go into menopause after a hysterectomy. This procedure might be recommended if you’re experiencing very heavy bleeding from your fibroids or if you have large fibroids. When recommended, the most minimally invasive procedure to perform hysteroscopy is advisable. Minimally invasive procedures include vaginal, laparoscopic or robotic approaches.
- Uterine fibroid embolization: This procedure is performed by an interventional radiologist who works with your gynecologist. A small catheter is placed in the uterine artery or radial artery and small particles are used to block the flow of blood from the uterine artery to the fibroids. Loss of blood flow shrinks the fibroids — improving your symptoms.
- Radiofrequency ablation (RFA): This is a safe and effective treatment for people with symptomatic uterine fibroids and can be delivered by laparoscopic, transvaginal or transcervical approaches.
There’s also a newer procedure called magnetic resonance imaging (MRI)-guided focused ultrasound that can be used to treat fibroids. This technique is actually done while you’re inside a MRI machine. You are placed inside the machine — which allows your provider to have a clear view of the fibroids — and then an ultrasound is used to send targeted sound waves at the fibroids. This damages the fibroids.
Are there any risks related to fibroid treatments?
There can be risks to any treatment. Medications can have side effects and some may not be a good fit for you. Talk to your healthcare provider about all medications you may be taking for other medical conditions and your complete medical history before starting a new medication. If you experience side effects after starting a new medication, call your provider to discuss your options.
There are also always risks involved in surgical treatment of fibroids. Any surgery places you at risk of infection, bleeding, and any inherent risks associated with surgery and anesthesia. An additional risk of fibroid removal surgery can involve future pregnancies. Some surgical options can prevent future pregnancies. Myomectomy is a procedure that only removes the fibroids, allowing for future pregnancies. However, people who have had a myomectomy may need to deliver future babies via Caesarean section (C-section).
How large do uterine fibroids need to be before being surgically removed?
The normal uterine size is the size of a lemon or 8 cm. There isn’t a definitive size of a fibroid that would automatically mandate removal. Your healthcare provider will determine the symptoms that are causing the problem. Fibroids the size of a marble for instance, if located within the uterine cavity, may be associated with profound bleeding. Fibroids the size of a grapefruit or larger may cause you to experience pelvic pressure, as well as make you look pregnant and see increased abdominal growth that can make the abdomen enlarged. It’s important for the healthcare provider and patient to discuss symptoms which might require surgical intervention.
Can fibroids be prevented?
In general, you can’t prevent fibroids. You can reduce your risk by maintaining a healthy body weight and getting regular pelvic exams. If you have small fibroids, develop a plan with your healthcare provider to monitor them.
Can I get pregnant if I have uterine fibroids?
Yes, you can get pregnant if you have uterine fibroids. If you already know you have fibroids when you get pregnant, your healthcare provider will work with you to develop a monitoring plan for the fibroids. During pregnancy, your body releases elevated levels of hormones. These hormones support the growth of your baby. However, they can also cause your fibroids to get bigger. Large fibroids can prevent your baby from being able to flip into the correct fetal position, increasing your risk of a breech birth or malpresentation of the fetal head. In very rare cases, you may be at higher risk of a pre-term delivery or a C-section delivery. In some cases, fibroids can contribute to infertility. It can be difficult to pinpoint an exact cause of infertility, but some people are able to become pregnant after receiving treatment for fibroids.
Outlook / Prognosis
Will fibroids go away on their own?
Fibroids can shrink in some people after menopause. This happens because of a decrease in hormones. When the fibroids shrink, your symptoms may go away. Small fibroids may not need treatment if they aren’t causing any symptoms.
A note from Cleveland Clinic
Uterine fibroids are a common condition that many people experience during their life. In some cases, fibroids are small and don’t cause any symptoms at all. Other times, fibroids can cause challenging symptoms. Talk to your healthcare provider if you experience any kind of discomfort or pain. Fibroids can be treated and, often, your symptoms can be improved.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy