At your last gynecological exam, your doctor told you she felt a mass in your uterus. She said not to worry, but made an appointment for you to get an ultrasound. Fibroids, she tells you, are very common. You nod along waiting to put your clothes back on and go, but once you leave the office, you wonder — wait, what exactly is a fibroid?

The uterus can be the biological home for a developing baby, but it can also be the home to different abnormal growths. Cysts and polyps are two of those growths, fibroids are another.

What is a fibroid?
Fibroids are the most common tumors of the female reproductive system. And although the term “tumor” might make you think of cancer, most fibroids (nearly 99 percent of them) are non-cancerous. Fibroids are composed of muscle cells and fibrous connective tissue in the uterus. Although most fibroids grow in the lining of the uterus, they can also grow elsewhere in the uterus: on the outer layer, in between the muscles, and in the wall of the cervix (the connection between the uterus and the vagina).The size of the tumor can range from a quarter of an inch, like the size of a pea, to several inches, like the size of a grapefruit, or even larger in the very extreme cases.

Some people can go their entire lives without knowing they have fibroids. For others, the symptoms can range from annoying to life-altering. People with fibroids can experience heavy bleeding during their periods, bleeding between periods, a pelvic pressure or fullness in their lower abdomen, pain during sexual intercourse, and lower back pain.

According to the National Institutes of Health, by age 50, 70 percent of white American women and 80 percent of African-American women had fibroids. Among women 25 to 44, about one-third of women have symptoms of fibroids. African-American women are more prone to having multiple fibroids.

Since fibroids often begin during childbearing years, some women discover these uterine growths when they’re trying to conceive. Fibroids can cause reproductive issues, including miscarriages, infertility, or early onset of labor. Women with fibroids may also find that they are more likely to be told they need a cesarean section. According to the American Congress of Obstetricians and Gynecologists, fibroids “are the reason for nearly 39 percent of all hysterectomies performed each year in the U.S.”

Why do women get fibroids?
Although researchers haven’t reached any definitive conclusions about why women develop fibroids, there are some factors that seem to increase the likelihood of having them.

Age: How old you are is a big factor in your risk for fibroids. Women in their 30s and 40s are especially prone, while women in their 20s are at lower risk. Fibroids feed off of estrogen, so when estrogen levels go down during menopause, so do fibroids.

Family history: If your mother had fibroids, then you’re at a three times higher risk of developing them too. Ask her if she ever dealt with fibroids and if or when she began experiencing symptoms.

Ethnicity: African-American women are more likely to develop fibroids with more severe symptoms and the greater possibility of multiple growths. One study in the American Journal of Epidemiology found a possible link between fibroid incidence and exposure to chemicals in hair relaxing products.

Weight: Women considered overweight or obese according to the Centers for Disease Control’s Body Mass Index saw higher rates of fibroids. This might be in part because of increased estrogen in obese women.

Diet: Eating red meat and pork can also increase the risk of fibroids. Women who ate more vegetables had lower rates of developing the non-cancerous tumors. Sufficient vitamin D also seemed to lower the odds of women developing fibroids. An hour of sun a day could help keep these growths in check.

Life events: Researchers at Boston University, as a part of their Black Women’s Health Study, found a higher incidence of fibroids among women who had been physically or sexually abused during childhood. The researchers think the link might exist because of the impact of stress on sex steroid hormones or potential exposure to sexually transmitted infections

What can you do to treat fibroids?
If you aren’t experiencing any symptoms from your fibroids, then you may not need to do anything more than monitor their growth. Small fibroids that stay small and don’t cause pain are the best-case scenario. You and your doctor can determine a frequency for ultrasounds to keep you worry-free. There is no one solution to fibroids given the differences in size, location, and symptoms.

However, if you are experiencing symptoms or you’ve discovered your fibroid in the midst of trying to conceive, you may need a medical solution to solve the problem. There are two main options: hormonal therapy or surgical intervention.

Hormonal therapy is the least invasive way to treat the growths. Those options could include hormonal injections, birth control pills, or a hormonal IUD. All three change your hormone levels, regulating estrogen or releasing progesterone. If you want to conceive, though, this option isn’t for you.

For larger fibroids or multiple ones, a surgical procedure may be the right option. This can include a focused ultrasound ablation, where waves of heat destroy fibroids tissue; surgical ablation, surgery to target the uterine artery that provides blood to a fibroid; myomectomy, or removal of the fibroids; or finally a hysterectomy, the removal of your uterus and possibly other reproductive organs depending on the severity of the fibroid.

If you have discovered you have fibroids, don’t panic. Talk to your doctor about next steps to ensure your best health.

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Camille Acker is a freelance writer living in Chicago and is a co-founder of The Spinsters Union. She is the proud owner of many, many books. See more at camilleacker.com.