At some point in their lives, most women will likely experience irregular bleeding during their periods or menstrual cycles. Stress, medications, major changes in exercise or nutrition, and several other health and lifestyle factors can cause cycles to fluctuate.

But if you’re regularly experiencing heavy bleeding during your period, your periods are consistently lasting longer than seven days or you’re spotting regularly between periods, it could be a sign of an underlying condition like uterine polyps.

Some studies estimate that up to 25% of women may experience uterine polyps sometime in their life. A uterine polyp doesn’t always cause symptoms, but if it does, it can have an impact on your daily routine and quality of life.

Below, we’ll discuss what you need to know about uterine polyps – what they are, their symptoms and when you should reach out to your doctor.

What are uterine polyps?

Uterine polyps are growths that attach to the inner wall of your uterus. They’re often called endometrial polyps because the endometrium is the tissue that lines the inside of the uterus. During your menstrual cycle, that uterine lining thickens and later sheds during your period.

These growths are usually noncancerous, although larger polyps have an increased chance of becoming cancerous, but this is rare and only about 0.3% of uterine polyps carry cancer cells. The average size of a uterine polyp is less than two centimeters across, but they can be as small as a few millimeters (think of a tomato seed) or as big as several centimeters (a ping pong ball or larger).

The most common uterine polyp symptoms to know

Uterine polyps don’t always have symptoms – some people may have uterine polyps and not even know it. However, uterine polyps can bleed at any time, and their size and placement can make it hard for fertilized eggs to implant in your uterine wall. Because of this, uterine polyps can cause a range of annoying menstrual symptoms and fertility issues.

If you’re experiencing some of these symptoms, it’s possible that uterine polyps could be the cause:

Abnormal bleeding or spotting during your period or throughout your menstrual cycle

Abnormal bleeding or spotting is the most common symptom of uterine polyps. An irregular period may show up with symptoms that include bleeding between your menstrual cycles, periods that consistently last longer than seven days or an extremely heavy period.

Postmenopausal bleeding

Postmenopausal bleeding happens when you experience vaginal bleeding more than a year after your last period. This can range from light bleeding (spotting) to a heavy flow like a regular menstrual cycle.

Some people experience pain

Although it’s uncommon, uterine polyps – especially large ones – can cause discomfort and a dull ache in the abdomen, pelvis or lower back.

Infertility

Due to their placement in the uterus, uterine polyps can cause infertility (the inability to get pregnant or carry a pregnancy to term).

Conditions that share similar symptoms with uterine polyps, and how to tell them apart

While abnormal bleeding is often the most common symptom of uterine polyps, the condition shares this symptom with several conditions. How can you tell them apart? A doctor can provide an official diagnosis, but if you’re assessing your symptoms, here’s how they might compare to other conditions.

Uterine polyps vs. uterine fibroids

Uterine fibroids are muscular tumors that grow inside the uterus, but they can also grow outside of it. Like uterine polyps, they’re usually noncancerous and both conditions share common menstrual symptoms like bleeding between periods as well as long, heavy periods and pelvic pain. But unlike uterine polyps, uterine fibroids symptoms can also include pain during sexual intercourse, constipation and frequent urination.

Uterine polyps vs. endometriosis

Endometriosis is a chronic condition where endometrial tissue – the tissue that lines the inside of your uterus – grows outside your uterus. Similar to uterine polyps, endometriosis can lead to abnormal menstrual bleeding and infertility.

However, the most common symptom of endometriosis is severe pelvic pain or lower back pain. That’s because the outside tissue growth doesn’t shed during a period, which can cause pain and inflammation. And while pelvic or lower back pain may also be a symptom of larger uterine polyps for some, it’s not as common.

Uterine polyps vs. polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a condition where your body doesn’t ovulate properly due to a hormone imbalance where not enough female hormones are produced and too many male sex hormones are produced.

Uterine polyps and PCOS can both cause infertility and an irregular menstrual cycle, but their biggest difference lies in how they affect your cycle. Uterine polyps are linked to abnormal bleeding and can cause you to bleed more than normal. On the other hand, PCOS can prevent you from bleeding as much as you should. While people with PCOS can have regular periods, some may have periods every five weeks or no period at all.

We don’t know the causes of uterine polyps, but we do know the risk factors

While the exact cause of uterine polyps is unknown, experts believe hormones play a role. Research indicates that uterine polyps tend to grow when your body produces excess estrogen.

Uterine polyps are also closely tied to your age – they’re rare in women under 20 and most common between 20-40 years old. Your risk of developing uterine polyps peaks in your 40s, as you approach menopause. While your risk significantly decreases once you reach menopause, some people do experience uterine polyps after.

Conditions that may increase the risk for uterine polyps

Your chances of developing uterine polyps can increase if you:

  • Are overweight. When you gain weight, the extra fat that your body develops will cause your estrogen levels to increase.
  • Receive hormone replacement therapy with a high dose of estrogen. This therapy is sometimes recommended for managing menopausal symptoms. It may be associated with polyp development and its related symptoms of irregular bleeding.
  • Take tamoxifen. This drug is used for breast cancer treatment and works against cancer cells in breast tissue, but it has cancer-like effects on endometrial tissue. Long-term tamoxifen use has been associated with uterine polyps, which can develop in 20-35% of women who take it for an extended period.
  • Have a family history of Lynch or Cowden syndrome. Lynch syndrome and Cowden syndrome are genetic conditions that run in families. Both are characterized by a genetic predisposition or increased risk of developing certain cancers.

Can uterine polyps be prevented?

While you can’t completely prevent uterine polyps from developing, there are some things you can do to reduce your risk of getting them. Your best chance lies in maintaining a healthy weight with a balanced diet and exercise. Your annual gynecological visit can also help spot uterine polyps early so treatment can begin as soon as possible.

How uterine polyps are diagnosed

It can be common for people to have uterine polyps and not know it. But if you think you’re experiencing symptoms of uterine polyps, diagnosis starts with a trip to your primary care doctor, OB-GYN or women’s health specialist.

When testing for uterine polyps, doctors will often start with a review of your medical history and a physical exam before moving on to further diagnostic testing with several minimally invasive procedures:

  • Medical exam: Your medical exam will include a review of your medical history – symptoms, medications and menstrual cycle – as well as a gynecological exam that may include a pelvic exam and Pap test. Your doctor will use this information to decide if additional tests or images are needed.
  • Transvaginal ultrasound: A transvaginal ultrasound is a test that looks at your reproductive organs. Your doctor or an ultrasound clinician will insert a probe into your vagina to capture a picture of your pelvic region and measure the thickness of your uterine lining. A thickened or irregular lining may require additional evaluation.
  • Sonohysterography: A sonohysterography (also called a saline infusion sonogram, or SIS) is an ultrasound exam where a salty fluid (saline) is inserted into the uterus to better evaluate your uterine lining.

Schedule an appointment with your doctor if you think you have uterine polyp symptoms

Most women experience an irregular period at some point in their lives. But if you’re regularly experiencing uterine polyp symptoms like irregular menstrual bleeding or bleeding between your periods, don’t ignore them. Make an appointment with a primary care doctor or women’s health specialist. They can help with diagnosis and treatment for uterine polyps.