Fibroids Causes, Types, Symptoms and Treatments

Up to 80 percent of people with uteruses will develop fibroids by the time they reach menopause.
Image Credit: Maskot/Maskot/GettyImages

While visiting my fiancé's family this summer, I excused myself to the bathroom, only to be met by unexpected vaginal bleeding. My period wasn't due for another two weeks, and though there was a possibility I could be pregnant, I thought it was very unlikely.


Rather than worrying, I popped in a tampon and assumed it'd stop. But, like clockwork, every time I would — ​ahem​ — have a bowel movement, there would be a bright spot of vaginal blood on the tissue. This kept up throughout my ovulation and then went away completely. When it happened again during my next cycle, I decided to book an appointment with my ob-gyn.

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Video of the Day

After a vaginal exam and two ultrasounds (one internal and one external), my doctor told me I had two small, olive-sized fibroids on the outside of my uterus. As it always seems to do, my mind went to the worst-case scenario, assuming this meant I had cancer.


But, much to my surprise (and relief), my ob-gyn said that fibroids are not only incredibly common, but most people assigned female at birth will have them at some point in their lives, yet very few will show symptoms.

I happen to be part of the small cohort that does show symptoms and my doctor reassured me that, more than likely, they'd go away on their own. She was right: Fast forward a few months later, and I haven't had any additional bleeding or other symptoms of fibroids.


Even so, as a very healthy person who intends to try to get pregnant in the near future, anything unusual in this region of my body makes me fearful. And as a lifestyle and wellness writer, I went into investigative journalism mode, finding anything and everything I could about these mysterious fibroids.

Because there's such a high chance that other people with uteruses may share my experience, I felt it would be worthwhile to share what I've learned about fibroids: what they are, how they fit into our reproductive health and how they're treated.


Consider this your fibroid 101 guide:

So, What Are Fibroids?

Also known as uterine myomas or leiomyomas, these mostly-benign growths start developing in people of reproductive age, Roohi Jeelani, MD, a reproductive endocrinologist and infertility specialist, tells


She echoes my ob-gyn in noting how common fibroids are, explaining that an estimated 1 in 3 people with uteruses will develop them at some point, and up to 80 percent will have them by the age of 50.


What Causes Them?

Of course, this was my biggest question to my ob-gyn, because health is a top concern for me. And more specifically, my reproductive health, because I do hope to become a mother soon.


Unfortunately, she didn't have much to offer, because we don't really know what causes them. There are some clues, however.

The Estrogen Connection

As Dr. Jeelani explains, while the cause of uterine fibroids has not been determined, we do know that they are hormone-dependent lesions caused by estrogen. Though my estrogen levels were normal according to my blood work, my mother has battled high-estrogen in the past.



Dr. Jeelani says genetics play a part because many people with fibroids have a family history of the condition, and certain ethnicities may be prone to getting them, too.

Associated Conditions

She also notes that those with high blood pressure or overweight may also have an increased chance of developing fibroids, although the reasons why aren't totally clear.


I don't have either, so for people like me, fibroids can seemingly develop out of the blue.

Types of Fibroids and Their Symptoms

According to the Mayo Clinic, the most common symptoms of fibroids include:

  • Heavy menstrual bleeding
  • Periods that last more than a week
  • Pain or pressure in the pelvic area
  • Back or leg pain
  • Having to pee a lot
  • Having a hard time emptying the bladder
  • Constipation


Steve Yu, MD, a gynecologic surgeon, explains there are several types of fibroids:

1. Intramural Fibroids

As the most common type, these appear within the muscular wall of the uterus. If they grow large enough, they can cause heavy menstrual bleeding, cramping and pelvic pain.

"They may also cause intestinal issues like constipation or bladder issues if they're large enough to put pressure on the bowels or bladder," Renee Wellenstein, MD, a double-board certified ob-gyn, tells

2. Subserosal Fibroids

Dr. Yu explains that subserosal fibroids form by stretching out the skin outside of the uterus, which is called "serosa." This means the bulk of the fibroid is within the outer skin. He says these generally produce symptoms if they grow larger, producing pelvic pain. And like intramural fibroids, they can cause bowel and bladder issues if they get big enough.

This is the type I have, but luckily, I didn't experience any discomfort.

3. Pedunculated Fibroids

When subserosal fibroids develop a stem — a slender base that supports the tumor — they are called pedunculated fibroids, Dr. Yu says. These fibroids usually do not cause heavy menstrual bleeding, but they can cause pain or discomfort if they grow too large. "They can also cause significant pelvic pain if the stalk twists and restricts the blood flow to the fibroid," he says.

4. Submucosal Fibroids

Dr. Yu says these types of growths develop in the uterus' inner muscle, stretching out the inner skin, called mucosa. They can cause extremely heavy menstrual bleeding and are frequently associated with symptomatic anemia, requiring urgent treatment.


5. Intracavity Fibroids

As you might guess from their name, these grow in the cavity of the uterus. These fibroids commonly cause heavy menstrual bleeding and, unfortunately, they can sometimes lead to infertility.

Do Fibroids Affect Fertility?

Because my greatest worry was about being able to carry a child, I was reassured to learn it'd be unlikely for the super-small fibroids on the outside of my uterus to pose an issue.

A fibroid's effect on fertility depends on its location and size, Dr. Wellenstein says. Generally speaking, it's large fibroids inside the uterus that could make getting and staying pregnant more difficult.

"If the fibroid is inside the uterine cavity, it may impact the implantation of a fertilized egg," she says. "If it is intramural and/or large, it may impact entry of sperm into the uterus if it's located by the cervix. Or it could impact entry of the egg into the fallopian tube or entry of a fertilized egg into the uterus if it's blocking the fallopian tubes."

Still, many people who have fibroids can get pregnant naturally, according to the Mayo Clinic, and most people who have them go on to have uneventful pregnancies and deliveries.

Related Reading

How Fibroids Are Treated

1. Watchful Waiting

Treatment for fibroids varies, but if they're like mine (i.e. relatively small and not causing pain or any other major issues), it's usually a wait-and-see process.

My ob-gyn recommended I schedule another ultrasound within the next year or when I decide to actively try to get pregnant. This can help me know if my fibroids have grown or moved, and help prepare me for the fertility journey ahead. Because my symptoms have gone away, though, it's likely my fibroids have too.


2. Medications

In some cases, Dr. Wellenstein says, a doctor may prescribe what's called a gonadotropin-releasing hormone, like Lupron or Zoladex, which could shrink the fibroid and control bleeding. These can come with side effects that are similar to menopause, though (think: hot flashes, breast and weight changes).

3. Surgery

If heavy vaginal bleeding or infertility is an issue, then a surgical procedure may be appropriate, Dr. Wellenstein says. There are several types, including:

  • Hysteroscopic myomectomy:​ The fibroid is "shaved" off of the inner uterine cavity
  • Abdominal or laparoscopic myomectomy:​ The fibroid is removed in its entirety)

In extreme cases, a doctor may choose to perform a hysterectomy, which is the removal of the entire uterus.


If you’re concerned about fibroids, book an appointment with your trusted ob-gyn. As I’ve learned, information is power — and the more you know, the better you can take care of yourself.




Is this an emergency? If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911.

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