What Are Uterine Fibroids?
Uterine fibroids, which your doctor may call leiomyomas or myomas, are tumors made of muscle that can grow on your uterus. They rarely turn into cancer. And if you get them, it doesn’t mean you’re more likely to get uterine cancer.
Fibroids can vary a lot in size, shape, and location. They can show up in your uterus, uterine wall, or on its surface. They can also attach to your uterus by a stalk- or stem-like structure.
Some are so small that your doctor can’t even see them with the naked eye. Others grow in big masses that can affect the size and shape of your uterus.
Uterine fibroids usually appear when you're of childbearing age – generally between 30 and 40 years old – but they can show up at any age. They’re more common in Black people than in White people. They also tend to show up earlier and grow quicker in Black people. Doctors don’t know why.
Uterine Fibroid vs. Polyp
Although they have similar symptoms, uterine fibroids and polyps are different. Uterine polyps are smaller and grow from the lining of the uterus. They can eventually block the opening of your fallopian tubes and stop you from getting pregnant. A small number of polyps, around 5%, turn out to be cancerous or have abnormal cells that are more likely to turn into cancer. It's why most gynecologists suggest removing them. Treatments include medication, surgery, and watchful waiting to see if polyps get better on their own.
Types of Fibroids
The type of fibroids you have depends on where they grow or form.
This type of fibroid grows within the wall of your uterus.
When a fibroid grows into your uterine cavity, doctors call it submucosal.
This type of fibroid happens on the outside of your uterus.
At times, submucosal or subserosal fibroids may hang from a stalk inside or outside of your uterus (called pedunculated).
Symptoms of Uterine Fibroids
Fibroids may cause very mild symptoms, no symptoms at all, or symptoms that are serious. The most common symptoms of uterine fibroids include:
Causes of Uterine Fibroids
Experts don’t know exactly why you get fibroids. Hormones and genetics might make you more likely to get them.
Hormones. Estrogen and progesterone are the hormones that make the lining of your uterus thicken every month during your period. They also seem to affect fibroid growth. When hormone production slows down during menopause, fibroids usually shrink.
Genetics. Researchers have found genetic differences between fibroids and normal cells in the uterus.
Other growth factors. Substances in your body that help with tissue upkeep, such as insulin-like growth factor, may play a part in fibroid growth.
Extracellular matrix (ECM). ECM makes your cells stick together. Fibroids have more ECM than normal cells, which makes them fibrous or ropey. ECM also stores growth factors (substances that spur cell growth) and causes cells to change.
Uterine Fibroid Risk Factors
A few things can raise your chances of getting uterine fibroids, such as:
- Getting your period at a young age
- Birth control pill use before age 16
- Vitamin D deficiency
- Eating too much red meat and not enough green vegetables, fruit, or dairy
- Family history
You’re more likely to get fibroids if close relatives like your mom or sister have had them.
Uterine Fibroid Diagnosis
Your doctor may suspect you have uterine fibroids just from feeling your uterus during a routine pelvic exam. If the shape of your uterus feels irregular or unusually large, they may order further tests, such as:
- Ultrasound. Ultrasounds use sound waves to take a picture of your uterus. A technician will place a device either in your vagina or on your belly to get the images. Then your doctor can see if you have fibroids and where and how large they are.
- Lab tests. Your doctor may want you to have blood tests to help figure out why you have fibroids. Your complete blood count can help them decide whether you have anemia (low levels of red blood cells) or other bleeding disorders.
- Magnetic resonance imaging (MRI). If your doctor needs more information after you have an ultrasound, you may also have an MRI. MRIs show more detailed images of fibroids and can help doctors decide the best treatment. Your doctor may also suggest an MRI if you have a large uterus or are close to menopause.
- Hysterosonography. In this test, a technician pushes a small amount of saline solution into your uterine cavity to make it larger. This helps them see fibroids that are growing into your uterus (submucosal fibroids) and the lining of your uterus. This is useful if you’re trying to get pregnant or have heavy periods.
- Hysterosalpingography. If your doctor needs to see if your fallopian tubes are blocked, you might have a hysterosalpingography. Your doctor uses dye to highlight your uterus and fallopian tubes on an X-ray to see these areas better.
- Hysteroscopy. Your doctor inserts a small telescope with a light attached into your cervix. Then, after injecting saline and expanding your uterine cavity, they can look at the walls of your uterus and fallopian tube opening.
Uterine Fibroid Treatment
There are many ways to treat fibroids. The treatment that works best for you will depend on whether you’re having symptoms, want to get pregnant, your age, and where your fibroids are.
Watchful waiting. If you have only mild symptoms – or no symptoms – your doctor may suggest you simply wait and see. Fibroids aren’t cancerous, and they may grow slowly or not at all. They also may shrink or go away after menopause.
Medications. Medications for fibroids treat your symptoms. Fibroids won’t go away but might shrink with some medications. They can also help with symptoms like pain and bleeding.
Birth control pills can reduce bleeding. Nonsteroidal anti-inflammatory medications such as ibuprofen or naproxen can ease pain. Vitamins and iron supplements can help with energy if you’re bleeding heavily and have anemia as a result.
Other medications include:
- Gonadotropin-releasing hormone (GnRH) agonists put you in a temporary menopause state by blocking estrogen and progesterone. This may shrink your fibroids. You take them as shots. Your doctor may choose this option before you have surgery.
- GnRH antagonists work in a different way to reduce or stop your period. Oriahnnand Myfembree combine GnRH antagonists with estrogen and progestin. You take them as pills.
- A progestin-releasing intrauterine device (IUD) inserted into your uterus can help control heavy bleeding. It also prevents pregnancy. But it might not be right for you if you have fibroids in the cavity of your uterus.
- Tranexamic acid (Cyklokapron, Lysteda)is a medication that doesn’t involve hormones. You take it on days you’re bleeding heavily to slow your flow.
Surgery. If you have moderate or severe symptoms, you may need surgery for relief. Options include:
- Myomectomy. This surgery takes out fibroids while trying to leave healthy tissue alone. This might be your best option if you hope to become pregnant in the future. There are multiple ways to do a myomectomy, from major abdominal surgery to laparoscopy (surgery done through one or more small cuts instead of one large one).
- Endometrial ablation. A surgeon uses either a laser, wire loops, boiling water, an electric current, microwaves, or freezing to remove or destroy the lining of your uterus. You may be able to have this minor surgery as an outpatient. Typically, you’ll stop having periods afterward, and you'll no longer be able to get pregnant.
- Uterine fibroid embolization (UFE), or uterine artery embolization (UAE). In this procedure, a doctor blocks the flow of blood to your fibroids by inserting gel or plastic particles into the nearby blood vessels. This makes the fibroids shrink.
- Hysterectomy. This surgery removes your uterus completely. This is the only way to cure fibroids entirely. It’s a major surgery, but your doctor has options for how to do it, including cutting through your belly or even laparoscopy.
Uterine Fibroid Complications
Most of the time, uterine fibroids aren't dangerous, but some people do have further health problems, such as anemia. Heavy blood loss and a drop in red blood cells cause the condition. Your doctor may suggest you take an iron supplement to avoid or manage anemia. People with severe anemia need donor blood (a transfusion).
Which Size of Fibroid is Dangerous?
Since most small fibroids don't cause symptoms, you probably won't need treatment. Instead, you and your doctor will keep an eye on your symptoms. Larger fibroids can cause serious health problems like severe pain and heavy bleeding. You'll need treatment based on your symptoms, the size of the fibroids, how many you have, and where they're located.
Most fibroids are between 2 and 6 centimeters. Fibroids larger than this can cause heavy bleeding, and your doctor may face challenges in removing them.
Uterine Fibroid Prevention
Fibroids can’t be prevented, but research suggests certain lifestyle habits can reduce your chances of having them.
One study found that high-sugar diets may be linked to a higher risk in some people. Another study found that eating fresh fruits and cruciferous vegetables like arugula, broccoli, cabbage, cauliflower, collard greens, and turnip greens could lower your odds. Cruciferous vegetables are rich in beta carotene, folate, vitamins C, E, and K, and other minerals. They’re also full of fiber.
Regular exercise also can lower your chances of getting uterine fibroids.
Uterine Fibroids and Pregnancy
Most people with uterine fibroids don't have trouble getting pregnant, but some fibroids can cause infertility or the loss of a pregnancy. If you're pregnant, the condition also raises the odds of health problems with your baby, such as being born too early and restricted growth.
Uterine Fibroids After Menopause
A drop in hormone levels after menopause tends to help shrink uterine fibroids, and you may notice your symptoms get better.
Can fibroids still grow after menopause?
It's unusual for uterine fibroids to keep growing after menopause. Talk to your doctor about any concerning fibroid symptoms after menopause, as they could be a sign of another health problem.
Uterine fibroids are noncancerous tumors made of muscle that can grow on the uterus. They vary in size, shape, and location, with symptoms including heavy periods, lower belly or back pain, painful sex, and peeing too often. We don't know the exact cause of the condition, but hormones, genetics, and other factors may lead to it. Treatment options range from watchful waiting for mild symptoms to medications and surgery for more severe cases. Lifestyle habits such as a healthy diet and regular exercise may lower your chances of getting uterine fibroids.