What actually are fibroids?

They're benign growths that develop from the smooth muscular tissue of your uterus, Dr. Alexander says. "They're derived from one cell that duplicates many times and becomes a round structure."

Researchers are still figuring out exactly what causes them. But, so far, they've learned that your genetics, hormones, and other growth factors play a role. For instance, you're more likely to develop uterine fibroids if others in your family have them, and some women find that their fibroids grow in response to monthly surges in estrogen and progesterone. We also tend to get more fibroids as we age.

What are the first signs you might have uterine fibroids?

It's estimated that as many as 75% of women have uterine fibroids at some point in their lives. But, for the the vast majority of people, they don't cause symptoms and thus go undetected.

When fibroids do cause symptoms, they frequently include pelvic pain and changes in your period. You might notice your period is unusually heavy, prolonged (at least seven days of bleeding), or stopping for a day before starting up again. And that can come with an aching back and frequent urination.

If you have symptoms, it's probably because your fibroid is in a really unfortunate spot. It may be pushing on your bladder, causing you to feel like you need to pee a lot. Or it may protrude into the uterine lining that sheds every month, which often causes longer, heavier periods.

Interestingly, the size of the fibroid doesn't always have too much to do with the level of pain patients experience. Dr. Alexander recalls one patient who had a fibroid that was larger than her entire uterus, but only noticed her pants getting tighter. On the other hand, Dr. Alexander says she's seen patients with "teeny" fibroids and very severe symptoms.

How do fibroids affect your fertility?

In most cases, fibroids don't interfere with pregnancy. But certain kinds, especially those in the inner cavity of the uterus, can make it harder for an embryo to implant and grow, Dr. Alexander explains. If you have these kinds of fibroids, doctors generally recommend getting them removed before trying to become pregnant — especially if you've had previous miscarriages.

In other rare cases, fibroids may block the path of sperm entering your cervix. Or they might "pinch your fallopian tubes, altering the ability of the fallopian tube to catch the egg," says Dr. Alexander. And because they can mess with your menstrual cycle, fibroids can make it difficult to predict the best time of the month for you to have sex.

How are uterine fibroids treated?

Because the growths aren't cancerous and tend to grow slowly (if at all), you don't always have to get rid of them. But if your symptoms are severe or you're attempting to become pregnant, there are many options out there.

To help with any menstrual irregularities, hormonal birth control is usually the go-to fix. There are also medications (such as Lupron) that can help shrink fibroids, but Dr. Alexander says these also cause pretty awful side effects; she only recommends them after a careful discussion that involves weighing the benefits and risks. Finally, minimally invasive surgical procedures can be used to remove individual growths if they are causing problems.

For many women, more fibroids develop. The only thing known to totally get rid of them is a hysterectomy (surgical removal of the uterus). "It takes a lot of counseling to understand the pros and cons of a hysterectomy," says Dr. Alexander, "and, generally speaking, it's the last resort." It's also done only after someone is finished having children (or if someone is sure she doesn't want to have kids).

The bottom line: "Depending on the location and size of the fibroid...you may or may not need to be worried," Dr. Alexander says. So it's important to work with your doctor to figure out the best course of action, which may end up being inaction.