Your Privacy

By using our website you consent that Clue may use cookies and third-party services, and collect your usage data under a unique identifier for the purposes of tracking, analysis, improvement of our website, and personalization purposes (such as showing you relevant Clue content).

Read more on our Privacy Policy how we use cookies.

Get the best of Clue for 25% less:Use code HELLO25 to get your exclusive web-only discount
Illustration of an uterus with fibroids

Illustration by Marta Pucci

Reading time: 6 min

Uterine fibroids: a common reason for irregular bleeding and pain

Top things to know:

  • Uterine fibroids are abnormal growths of muscle tissue that form in or on the walls of the uterus

  • Symptoms include irregular bleeding between periods and pelvic pain

  • Estrogen and progesterone play a role in the growth of fibroids

  • You might not notice them, but if they become problematic, they are treatable

Like uterine polyps, uterine fibroids are a common cause of changes in bleeding and period pattern.

While polyps are more likely to develop around the time of menopause, fibroids most often develop during the reproductive years. Here’s how to know if you have fibroids.

What they are

Uterine fibroids are abnormal growths of muscle tissue that form in (or on) the walls of the uterus. Fibroids are benign (not harmful/life threatening), but can cause symptoms such as irregular vaginal bleeding and pelvic pain (1,2). Uterine fibroids are sometimes called myomas or leiomyomas in medical literature.

Uterine fibroids are very common. About 3 in 4 women may have them at some point in their lives (3). They are most common during the reproductive years (2,3), and are more likely to occur in people of African ancestry (4). Uterine fibroids most often cause no symptoms at all (5) and often shrink after menopause (6,7). In other cases, untreated fibroids may lead to problems such as heavy bleeding, anemia, pelvic pain or pressure, fertility changes, and complications during pregnancy (1,2,8). Symptoms depend on the size, location, and number of fibroids.


An illustration of a five star rating

Track your menstrual cramps with Clue.

  • Download the Clue app on the App Store
  • Download the Clue app on the Play Store
default image

If you think you may have uterine fibroids, tracking your bleeding, pain, and any other symptoms with Clue can provide your healthcare provider with information that may help with diagnosis and in forming a treatment plan. Early treatment can reduce the risk of complications.

What you might notice

Some of the most common symptoms of uterine fibroids are:

  • Periods that are heavy, long, and/or painful (1,9)

  • Irregular bleeding (9)

  • Pelvic pressure or pain (2,10)

  • Frequent urination and difficulty emptying the bladder (1)

  • Constipation (10)

  • Difficulty getting pregnant or carrying to term (2)

In rare cases, uterine fibroids can become very large, twisted, or infected. These situations can create intense symptoms, and may require immediate medical treatment (11,12).

Some studies show that pregnancy may cause fibroids to grow slightly bigger in up to 1 in 3 people (2,13). This might make some symptoms more noticeable. The most common complication of uterine fibroids in pregnancy is pain, usually felt in the second and third trimesters (14,15).

Why they happen

Uterine fibroids occur when muscle cells in the uterus multiply too many times. As cells multiply, lumps of various shapes and sizes are formed. They can be numerous or few—some people might only have one. These lumps can grow on the inner and outer surfaces of the uterus, as well as within the uterine wall.

Research shows the hormones estrogen and progesterone play a role in the growth of uterine fibroids. This is probably why fibroids tend to shrink after menopause, when production of these hormones decreases (6,7).

Some people are more likely than others to develop uterine fibroids, and in fact fibroids may be inherited genetically (16). This means someone is more likely to develop fibroids if a family member has had them. People of African ancestry are significantly more likely to develop them (4). Someone is also more likely to have uterine fibroids if they have hypertension (17,18), or polycystic ovary syndrome (19). They are more common in people who have an earlier age at first menstruation (menarche) (4), and people who have not given birth, though this may be because women with fibroids may have difficulty conceiving (2). Maintaining a diet high in red meat consumption may also increase the risk of uterine fibroids (20), as may beer consumption (21).

Different types of fibroids create different symptoms. Fibroids embedded within the uterine wall (intramural fibroids) can change the shape of the uterus, which may cause changes in fertility (22). Fibroids that project into the inside of the uterus (submucosal fibroids) may also cause difficulty in becoming or staying pregnant (23).

Why get them checked out?

Uterine fibroids are generally harmless and often go away on their own. When symptoms occur, however, untreated fibroids can interfere with a person’s quality of life and may lead to complications such as anemia. Anemia is a condition when the body doesn’t have enough healthy red blood cells to function properly. This can happen when uterine fibroids cause heavy bleeding (7).

Some uterine fibroids may also interfere with the probability of becoming pregnant, and may increase the chance of miscarriage, but more research is needed here (22,23). In these cases, treatment can help people become and stay pregnant.

Rarely, uterine fibroids can become very large, twisted, or infected. These situations can create symptoms that are intense, and may require immediate medical treatment (11,12).

How they’re diagnosed

A healthcare provider will probably ask questions about symptoms, medical, and menstrual history. Some uterine fibroids are diagnosed with a physical exam. Other diagnostic methods may include:

  • A pelvic ultrasound (sonogram)

  • An MRI

  • A sonohysterogram (an ultrasound performed after the uterus is filled with fluid) (24)

What you can do about uterine fibroids

You and your healthcare provider may choose to leave fibroids with mild symptoms untreated. Tracking your symptoms can then help you know if your fibroids are changing, and at what point a treatment plan might be helpful. When fibroids do become problematic, there are many different options for managing and treating them, and for preventing their future formation:


In some cases, hormonal medications are prescribed to treat uterine fibroids. These include Selective Progesterone Receptor Modulators (SPRM) which change the effect of progesterone in the body, and Gonadotropin Releasing Hormone (GnRH) Agonists which block the body’s production of both progesterone and estrogen. These medications have been shown to lessen the size and number of uterine fibroids over time in people of reproductive age (25,26).

Lifestyle Changes

Maintaining a healthy weight may help lessen the occurrence uterine fibroids (16,27). Getting enough exercise and eating a balanced diet may also help with this. Specifically, a diet low in red meat and high in green vegetables may help to lessen the prevalence and severity of fibroids in some people (20).

Non-surgical procedures

Some symptomatic uterine fibroids may be destroyed through non-invasive procedures like uterine artery embolization and radiofrequency myolysis. These procedures cut off blood supply to fibroids. MRI-guided focused ultrasound surgery (FUS) is an example of a newer technique that uses soundwaves to destroy fibroids (25).


Uterine fibroids are sometimes treated with minimally invasive surgical procedures, via the abdomen or pelvis. Some cases of fibroids may be treated with a procedure called an abdominal myomectomy, in which problematic fibroids are surgically removed (25). In severe cases, a hysterectomy, or a removal of the uterus, may be performed (25).

What to track in Clue

Essential to track:

  • bleeding patterns

  • pain

Helpful to track:

  • blood volume

  • stool

  • sex (if trying to get pregnant)

an illustration of the Clue flower
an illustration of the Clue flower

Live in sync with your cycle and download the Clue app today.

Was this article helpful?

You might also like to read

Menstrual Cycle

Cycle tracking puts you in charge

Clue’s Chief Medical Officer, Lynae Brayboy, shares six ways tracking with Clue can really help you–and others.

Popular Articles

an illustration of the Clue flower
an illustration of the Clue flower

Live in sync with your cycle and download the Clue app today.