For a few days each month, you probably expect those familiar period cramps and pains to creep in. In the past, a heating pad and an over-the-counter pain reliever may have helped you get through the worst of it. But recently you’ve noticed your periods have become more painful – or even a feeling of pelvic pressure or fullness throughout your menstural cycle. You might have noticed your periods have gotten heavier, too.

What’s going on? One possibility is the growth of a uterine fibroid.

Uterine fibroids are very common. In fact, millions of women walk around with uterine fibroids every day and may not know it. But if your periods seem to have gotten more painful and heavier, it could be a sign of an underlying condition.

Read on to learn more about what uterine fibroids are, what causes them, common fibroid symptoms and signs, how they’re diagnosed and more.

What are uterine fibroids?

Uterine fibroids are noncancerous growths that develop in the uterus, most often during reproductive years – usually in your 20s or 30s. Also called leiomyomas or myomas, uterine fibroids grow on the walls of the uterus and can range in size from a quarter of an inch to the size of a melon.

How do uterine fibroids grow?

Fibroid growth is linked to increased hormone levels, specifically estrogen and progesterone. This is why fibroids are most common during female reproductive years when these hormones are in greater supply in the body.

Types of uterine fibroids and where they grow in the uterus

There are three main types of uterine fibroids.

Intramural fibroids

Intramural fibroids grow between the muscles of the uterus. They can grow in the front of the uterus (anterior intramural fibroid), the back of the uterus (posterior intramural fibroid), and the upper part of the uterus (fundal intramural fibroid.) Even though it’s not as common, this type of fibroid can affect fertility and viability of a pregnancy depending on the size and location.

Subserosal fibroids

Subserosal fibroids grow on the outside, or the outer wall, of the uterus. They can be attached to the uterine wall directly or attached to the uterus by a thin connective tissue. If this type of fibroid is attached by a thin tissue, they are classified as a pedunculated subserosal fibroid.

Submucosal fibroids

Submucosal fibroids grow on the inner lining of the uterus, which is called the endometrium. This is the part of the uterus that thickens and sheds during a menstrual cycle. This is also the part of the uterus where an embryo would implant for pregnancy. So of all the fibroids types, submucosal fibroids are the most likely to cause heavy bleeding, or trouble getting or staying pregnant.

Submucosal fibroids can also be pendulated, hanging from a stalk inside the uterus.

The differences between uterine polyps and fibroids

Polyps and fibroids are both growths located in the uterus, but they are made up of different types of tissue. Uterine fibroids are made of the dense, connective fibrous tissue from smooth muscle. Polyps are made up of the same tissue as the inner lining of the uterine wall.

Some polyps can develop into cancer over many years while uterine fibroids are rarely cancerous. Also, uterine polyps are typically found in women approaching menopause while uterine fibroids are most common during menstruating years.

Common symptoms of uterine fibroids

Many women who have uterine fibroids don’t have any symptoms. But for those who do, their symptoms can range in severity and are influenced by the location, size and number of fibroids.

Some of the most common symptoms of uterine fibroids are:

What does it feel like when you have fibroids?

Uterine fibroid symptoms feel different for everyone depending on the location, size and number of fibroids. Some women will feel no symptoms, while others will feel mild to moderate discomfort. And still others may feel heaviness or pressure in their lower abdomen or pelvis, often accompanied by discomfort that makes it difficult to stand, lie face down or exercise without noticing it.

If you’re concerned about any symptoms you’re experiencing, the best first step is to see a primary care doctor or a women’s health specialist like an OB-GYN.

We’re learning more about the causes of uterine fibroids

While it’s not yet fully known what causes uterine fibroids, research has shown that they may form from stem cells found in the smooth muscle. There are two main factors:

  • Hormones – Estrogen and progesterone, two hormones that stimulate the growth of the uterine wall during the menstrual cycle and help support pregnancy, have been linked to fibroid growth.
  • Genetics – Genetics appears to play a role in whether someone develops fibroids. You may be genetically predisposed to developing fibroids because of your family history.

Uterine fibroids and pregnancy

In many cases, uterine fibroids don’t interfere with a person’s ability to become pregnant. But as we mentioned earlier, it’s possible that they could lead to infertility or pregnancy loss, especially submucosal fibroids, as they’re attached to the inner lining of the uterus and can cause excess bleeding. Uterine fibroids may also increase the risk of developing certain pregnancy complications like placenta previa, placental abruption, fetal growth restriction and preterm delivery.

Uterine fibroids after menopause

Uterine fibroids are most common in women during their childbearing years. But in very rare circumstances, uterine fibroids can continue to develop in women experiencing menopause, especially if they are undergoing hormone therapy to maintain their estrogen and progesterone levels. If you’re experiencing any symptoms of fibroids, you should talk with your primary care doctor or clinician, or your OB-GYN.

How are uterine fibroids diagnosed?

Whether you’re experiencing symptoms or not, uterine fibroids may be found by a primary care doctor, OB-GYN or another women’s health specialist during a routine pelvic exam. During a pelvic exam a clinician can sometimes feel the size or shape of the uterus is irregular.

If your doctor believes you have fibroids, there are several tests and exams they can order to confirm a diagnosis:

  • Ultrasound – During a uterine fibroid ultrasound, a technician will place a device either inside of your vagina or along your abdomen to get images that your doctor can review to understand the size and location of the fibroids.
  • MRI – A magnetic resonance imaging (MRI) test can be performed after an ultrasound if your doctor needs more detailed images of the fibroids to determine the best possible treatment. You may also need an MRI if you have a large uterus or are close to menopause.
  • Hysterosonography – If you are trying to get pregnant or are experiencing heavy menstrual bleeding, your doctor may recommend a hysterosonography. During this process, saline is inserted into your uterine cavity to enlarge it, allowing your doctors and technicians to more easily see where the fibroids are growing.
  • Hysterosalpingography – During a hysterosalpingography, dye is used to highlight your uterus and fallopian tubes on an X-ray. It may be performed if your doctor believes that your uterine fibroids have caused blockage in your fallopian tubes.
  • Hysteroscopy – Similar to a hysterosonography test, saline is used to expand your uterine cavity, allowing your doctor to insert a small telescope into your cervix to understand the extent of fibroids on the walls of your uterus and fallopian tube opening.

Are uterine fibroids serious?

Generally speaking, uterine fibroids aren’t dangerous for most people. But for some, they can cause discomfort and have a big impact on the quality of life. In some cases, they can also lead to complications, such as excessive blood loss and anemia that may require a blood transfusion. As we mentioned earlier, it’s very rare that uterine fibroids are cancerous.

Do uterine fibroids go away on their own?

Uterine fibroids can go away on their own, but it’s relatively rare. In these instances, the blood supply to the fibroid will inexplicably get cut off, and the growth will shrink as a result. For example, if you develop uterine fibroids during pregnancy, they can shrink and disappear after giving birth. Other fibroids may regress during menopause, but this isn’t always the case.

Do uterine fibroids need to be removed?

Since they’re benign growths, fibroids that aren’t causing any issues don’t need to be removed right away or possibly at all. It’s not uncommon for people to live with uterine fibroids for years because they’re able to manage their symptoms. This is called watchful waiting.

But when uterine fibroids are causing excessive period pain or bleeding, pelvic discomfort or other issues, they need to be removed to resolve symptoms.

It’s important to know that uterine fibroids can continue to grow in size. It’s also possible that more may develop. This means uterine fibroid symptoms can become more severe or serious for some people. For example, bleeding may become even heavier or any associated cramping might become more uncomfortable or painful. Other conditions like anemia can also develop.

So, it’s important to listen to your body and seek care when you notice an increase in symptoms or their severity. Luckily, there are a range of uterine fibroid treatment options to alleviate short- and long-term symptoms.

Talk to a doctor about your uterine fibroid symptoms

If you’re experiencing symptoms like excessive or painful bleeding during periods, bleeding between periods, or pelvic pressure or discomfort, make an appointment with your primary care doctor or women’s health specialist. They’ll review your medical history, listen to your symptoms and may perform a pelvic exam or other tests to determine if a fibroid may be the cause of your symptoms.