What to Know About Endometrial Hyperplasia

Medically Reviewed by Jabeen Begum, MD on November 17, 2021
4 min read

Endometrial hyperplasia is a condition in which the lining of your womb becomes too thick. In some women, this can lead to cancer of the uterus. Endometrial hyperplasia is rare. It affects about 133 out of 100,000 women.

Your endometrium is the lining of your uterus (womb). During your menstrual cycle, your endometrium changes. The estrogen that your ovaries produce makes your endometrium thicken. This prepares your uterus for possible pregnancy.

After the release of an egg from your ovary (ovulation), your progesterone level increases. This hormone gets your uterus ready to receive an egg. If pregnancy doesn’t happen, your estrogen and progesterone levels drop. This leads to the shedding of the lining (menstruation).

If there's a hormonal imbalance, however, your endometrium can thicken and grow too much. This abnormal growth is endometrial hyperplasia.

There are two types of endometrial hyperplasia based on the kind of cell changes in your endometrium:

  • Simple endometrial hyperplasia (without atypia). This type consists of normal cells that aren’t likely to be cancerous. This condition may improve without treatment. 
  • Simple or complex atypical endometrial hyperplasia. This type is precancerous and results from an overgrowth of abnormal cells. If untreated, it may turn into uterine or endometrial cancer.

Endometrial hyperplasia is caused by too much estrogen and not enough progesterone. If there’s too little progesterone, your uterus isn’t triggered to shed its lining (menstruation). The lining continues to thicken due to estrogen. The cells in the lining may crowd together and become irregular.

The symptoms of endometrial hyperplasia include:

  • Heavy menstrual bleeding
  • Bleeding that happens after menopause
  • Menstrual cycles that are shorter than 21 days

Your doctor will conduct a physical exam and take into account your medical history. They may ask about your symptoms and menstrual history, such as the ages you started menstruation and menopause.

Many different conditions can cause unusual bleeding, so your doctor may carry out some of these diagnostic tests:

Ultrasound. Your doctor may perform a transvaginal ultrasound to see if your lining is thick. They will insert a small device into your vagina. This device uses sound waves, which are converted into images of your uterus. If your endometrium is thick, that may mean that you have endometrial hyperplasia.

Biopsy. You may also need to have a biopsy. Your doctor will remove a sample of tissue from your uterus lining. This will be tested in a lab to see if it’s cancerous.

Hysteroscopy. A hysteroscope is a thin, lighted, flexible tube. Your doctor will use it to look inside your uterus for any abnormalities. They may also perform a biopsy or a dilation and curettage (D&C).

During a dilation and curettage, your doctor will open (dilate) your cervix, which is the opening of your uterus. They’ll then use a thin instrument called a curette to remove tissue from your uterus.

Most cases of endometrial hyperplasia are treatable. A common treatment is progestin, a manmade progesterone.

Your doctor may prescribe progestin in a few different ways:

  • Orally
  • Via injections 
  • In vaginal cream
  • In an intrauterine device (IUD)

You’ll likely need to be treated for at least six months. You’re at a higher risk of relapse if you’re obese or treated with oral progestin, and you may need follow-up appointments every year.

Hysterectomy. Your doctor may recommend a surgery to remove your uterus (hysterectomy) if:

  • During your treatment, atypical endometrial hyperplasia develops
  • After 12 months of treatment, there’s no improvement
  • You have a relapse or worsening of your condition 
  • Your bleeding doesn’t stop

After a hysterectomy is performed, you’ll no longer be able to get pregnant. Talk to your doctor to find out what’s the best treatment for you.

You’re at a higher risk for endometrial hyperplasia if you have these risk factors:

  • Menopause transition (perimenopausal) or menopause
  • A family history of colon, ovarian, and uterine cancer
  • Diabetes
  • Having never been pregnant
  • Obesity
  • Polycystic ovary syndrome (PCOS)
  • Smoking
  • Gallbladder disease
  • Thyroid disease
  • Certain breast cancer treatments 
  • Hormone therapy
  • Early age of menstruation
  • Older age of menopause

You can’t prevent endometrial hyperplasia, but you can lower your risk with these steps: 

  • Quit smoking.
  • Maintain a healthy weight.
  • If you use hormone therapy, take progestin along with estrogen.
  • Take birth control to regulate your menstrual cycle and hormones.

If left untreated, atypical endometrial hyperplasia can become cancerous. About 8% of women with simple atypical endometrial hyperplasia who don't get treatment develop cancer. Nearly 30% of those with untreated complex atypical endometrial hyperplasia develop cancer.