So you’ve just come back from your annual gynecological exam and your doctor told you that you might have uterine fibroids. What are fibroids? Are they dangerous? Can they be removed? Should they be removed?

First, take a deep breath. Fibroids are pretty common — between 20-70 percent of women will develop fibroids during their reproductive years. And they’re almost always (99 percent of the time) harmless.

But that doesn’t mean you should ignore them. Fibroids can cause complications like excessive bleeding and reproductive problems. Johns Hopkins gynecologist Valerie Baker, M.D., who specializes in treating uterine fibroids, explains how women can manage these common growths.

What are uterine fibroids?

Uterine fibroids are benign, or noncancerous, fibrous growths that form in the uterus. They’re very common. They can grow on the outside of the uterus (called subserosal fibroids), inside the muscle of the uterus (called intramural fibroids), or into the uterine cavity (called submucosal fibroids).

What causes fibroids?

There's definitely a genetic component, but we haven’t found any lifestyle factors that cause uterine fibroids.

What are the symptoms of fibroids?

Some women have no symptoms at all from fibroids and don't even know they have them. Other women have severe symptoms. Symptoms can include very heavy menstrual cycles. Some women have so much bleeding that they become anemic —that's a hallmark symptom. Fibroids that cause severe bleeding are usually closer to the uterine cavity.

Some women can have very large fibroids that cause the uterus to be up to 10 times its normal size. This causes what we call “bulk symptoms.” For example, a woman may feel that her uterus is very enlarged, like she's pregnant. She may have related symptoms due to its bulk size, like constipation or increased urination.

Can other issues cause these symptoms?

If a woman sees her doctor because she is having increased bleeding or a heavy menstrual cycle, the doctor will likely check for uterine fibroids, but these symptoms can also be due to things such as uterine polyps, dysfunctional uterine bleeding or bleeding caused by hormonal imbalances.

How are fibroids diagnosed?

Fibroids are typically diagnosed by ultrasound. That’s really the easiest way to see the uterus, and fibroids are usually very easily seen. The first step might be an exam by your doctor, where he or she would feel an enlarged uterus and suspect fibroids. For smaller fibroids, the only way to diagnose them is often with ultrasound. Some doctors may choose to also do an MRI of the pelvis as a way to see exactly where the fibroids are.

How are fibroids treated?

It depends on symptoms and size. For example, if a woman has fibroids inside the uterine cavity, we may do a hysteroscopic myomectomy, in which we look inside the uterus with a camera. At the same time, we can do a surgical procedure to remove the fibroids if they’re just inside the uterine cavity.

If a woman has severe symptoms, and if the fibroids are in the muscle or outside of the uterus, surgery may be the best option. In that case, robotic-assisted laparoscopic myomectomy is more common. This is a minimally invasive procedure that involves making four to five small incisions in the abdomen. We then use small instruments attached to robotic arms to remove the fibroids through these very small openings.

In severe cases, a woman would have an open myomectomy, which is also called abdominal myomectomy. This surgery requires an incision either in the bikini area or a vertical incision along the abdomen. We then remove the fibroids through this incision.

Some nonsurgical management of uterine fibroids may include medicine that can help suppress their growth, such as birth control pills. There's also a medication called leuprolide acetate, which can help shrink them.

How might fibroids might affect fertility and pregnancy?

Their impact on fertility depends on the location and the size of the fibroids, as well as the type of symptoms a woman has. Fibroids inside the uterine cavity can stop an embryo from implanting, which prevents it from growing into a fetus. Larger fibroids—about four centimeters or more—that are in the muscle of the uterus can also impact implantation. Fibroids that are inside the muscle of the uterus might block the fallopian tubes, which can cause infertility.

Sometimes fibroids can affect the mode of delivery of a baby. For instance, if a woman has a fibroid in the lower part of her uterus, it might make it difficult for the cervix to open completely, which might make a C-section difficult.

It's really important for each woman and her obstetrician to have a game plan for delivery.