5 Common Causes of an Enlarged Uterus—Plus How to Tell If You Have One

Your uterus, which, on average, is about the size of an apple, is designed to expand during pregnancy to house a growing fetus. But if you’re not pregnant, a swollen or enlarged uterus is typically a sign of an underlying reproductive condition.

Often, you can’t tell that your uterus is bigger than it should be. (Because…it’s inside your body.) Instead, conditions that cause an enlarged uterus are usually marked by other symptoms, especially around your period, Kenosha Gleaton, MD, a board-certified OB/GYN and medical advisor for Natalist, tells Well+Good.

Here’s a closer look at what those conditions can be, and what treatment entails for each cause. Plus, when to reach out to your healthcare provider for enlarged uterus symptoms.

5 causes of an enlarged uterus

There are a few main causes of an enlarged uterus that your healthcare provider can detect through ultrasounds and other gynecologic exams. While some are benign, others may require further testing and treatment. Here’s a breakdown of the most common causes to know.

1. Fibroids

Fibroids, or benign growths that form on the lining of the wall of the uterus, are the most common cause of an enlarged uterus, Dr. Gleaton says. Most times, fibroids are so small that they don’t cause symptoms. But, “if the growth becomes too large, it can cause heavy bleeding during periods, lower back and pelvic pain, and bloating in your stomach,” she adds.

How to treat it

Treatment for fibroids will depend on the size of the growths and the kinds of symptoms they’re causing. Small fibroids that are mildly uncomfortable often don’t require treatment, but bigger ones might need to be removed surgically.

2. Adenomyosis

Adenomyosis is a gynecologic condition where tissue from the uterine lining grows into the uterine muscle, causing the uterus to become thicker and expand. While anyone can develop the condition, “it’s mostly seen in women during the mid-stages of life around 40 to 50 years old,” Dr. Gleaton says. Symptoms of adenomyosis are often similar to those of large uterine fibroids: heavy bleeding and cramping during periods, back and pelvic pain, and bloating.

How to treat it

One of the first lines of treatment for adenomyosis is medication that stops ovulation (i.e., hormonal birth control) because symptoms tend to worsen around menstruation. “Hormonal therapies can help treat symptoms such as heavy periods, painful periods, and painful sex,” says Dr. Gleaton. “In rare, severe cases, surgery may be needed to remove the uterus (aka a hysterectomy), but again, that’s very rare and symptoms are largely addressed with medication.”

3. Ovarian cysts

Your ovaries (reproductive organs that hold eggs) sit outside of your uterus, but certain conditions that affect them can affect your uterus, too. This includes ovarian cysts, which are benign, fluid-filled sacs that can grow on and cover your ovaries. Often, these cysts can cause intermittent, one-sided abdominal pain along with bloating and a feeling of abdominal pressure or fullness.

While ovarian cysts are harmless, in rare cases, they can rupture or burst, which may cause overall swelling in that region.

How to treat it

Most ovarian cysts will break and dissipate on their own, but if yours is causing persistent pain, your healthcare provider may be able to offer some pain relief suggestions. This can include over-the-counter (OTC) pain relievers like Ibuprofen or Tylenol, taking a hot bath, or using a heating pad. To prevent future cysts from forming, they may suggest starting hormonal birth control. If a cyst is too large, your healthcare provider may recommend getting it surgically removed.

Additionally, if you have sudden and severe pelvic pain, a fever, weakness, lightheadedness, or vomiting, it’s best to seek immediate medical care. These could be signs your cyst has ruptured or burst.

4. PCOS

Polycystic ovary syndrome (aka PCOS) is a disorder where the body produces too much of the hormone androgen (testosterone), causing irregular periods, facial hair growth, acne, and weight gain, among other symptoms. The condition can also cause the inner lining of your uterus to become slightly thicker, but because the thickening happens on the inside, it doesn’t usually make a person’s uterus larger, per se, Dr. Gleaton says. Additionally, PCOS is often associated with higher infertility rates, as the condition can sometimes make it harder for you to get pregnant.

How to treat it

Certain lifestyle changes are often encouraged to help manage the symptoms of PCOS, including daily exercise, reducing sugar and refined carbohydrate consumption, and maintaining a healthy weight. Medical treatments, on the other hand, will typically vary. If you don’t plan to get pregnant anytime soon, your healthcare provider might recommend hormonal birth control to help regulate your periods or other types of hormone therapy—like progestin therapy—to help stabilize hormone production.

That said, if you wish to get pregnant, your healthcare provider might prescribe medication to encourage ovulation, or other fertility treatments—like in vitro fertilization (IVF)—to help.

5. Endometrial cancer, in rare cases

Rarely, an enlarged uterus can be a sign of endometrial or uterine cancer—which happens when cells mutate and grow into a tumor in the lining of the uterus. The only early signs may be irregular periods, but advanced cancers with larger tumors can cause abdominal pain, bloating, or feeling full soon after eating.

How to treat it

Endometrial cancer is often diagnosed through pelvic exams, ultrasound imaging, or a biopsy (i.e., taking a sample of uterine tissue for testing). From there, depending on the severity, it’s treated with surgery, radiation therapy, chemotherapy, or hormone therapy.

Thankfully, when this type of cancer is detected early, it can be curable. “That’s why it’s so important to stay up to date on your pelvic exams and speak with your doctor immediately if you’re experiencing any [abnormal] symptoms—even if you think they are not serious,” Dr. Gleaton says.

Other symptoms of an enlarged uterus

Because your uterus is inside your body, you can’t see or feel when it’s enlarged. That said, you can see or feel the effects of an underlying condition making your uterus larger. Usually, these effects take the form of abdominal or period-related symptoms, says Dr. Gleaton. This may include symptoms like the following:

• Bloating
• Abdominal or pelvic pain
• Cramping
• Constipation
• Feeling of abdominal pressure or fullness
• Heavy or long periods
• Painful periods
• Spotting
• Frequent urination
• Painful sex

Other times, an enlarged uterus may not cause any symptoms, like when you have small fibroids or ovarian cysts. In that case, the only way you’d find out whether you have an enlarged uterus is during a pelvic exam. “Your OB/GYN will be able to feel it and diagnose the cause,” Dr. Gleaton says.

Does an enlarged uterus cause weight gain?

In short, no. An enlarged uterus does not contribute to belly fat or weight gain overall. But it can make your abdomen feel bloated, full, or heavy, which may feel as though you’ve gained weight (when it’s likely you haven’t). If you’re concerned about bloating or sudden weight gain, reach out to your healthcare provider.

What does treatment look like?

Treatment for an enlarged uterus varies greatly depending on the cause. “It’s important to get to the root cause to identify which treatment is best for you,” says Dr. Gleaton.

If your healthcare provider notices that your uterus feels larger than normal during a pelvic exam, they might be able to diagnose the underlying condition based on symptoms alone. Other times, they’ll need to perform imaging tests—like an ultrasound or MRI scan—to learn more about what’s driving the abnormal change.

Once you’ve figured out the cause, you and your healthcare provider can determine the best way to treat it. You might opt for things like:

• OTC pain relievers (ibuprofen, naproxen, or acetaminophen)
• Hormonal birth control like the pill, patch, or ring
• Other hormonal medications like gonadotropin-releasing hormone medications and danazol
• Surgery

When to see a healthcare provider

Any time you experience symptoms that are considered “out of the ordinary” for your body—like persistent pelvic pain, abnormal vaginal discharge, bleeding, etc.—it’s best to let your healthcare provider know. You may have an underlying condition that causes an enlarged uterus and other disruptive symptoms.

Even relatively harmless problems—like benign fibroids or cysts—”can impact your quality of life,” Dr. Gleaton says. Plus, they can potentially make it harder to get pregnant if you’re planning to do so. So, make sure you’re visiting your healthcare provider regularly for pelvic exams and other preventative care—especially to rule out more serious issues like endometrial cancer.