What Is Endometrial Hyperplasia

Are you experiencing heavy periods or periods that last longer than normal, or are you having periods after menopause? If so, there is a chance that you may have endometrial hyperplasia.

In endometrial hyperplasia, the uterine lining thickens, which may result in abnormal vaginal bleeding. There are different types of endometrial hyperplasia depending on its severity. In severe cases, it may result in endometrial cancer.

Keep reading if you would like to know more about the symptoms of endometrial hyperplasia, its causes, and how it is diagnosed and managed. 


Endometrial hyperplasia is a thickening of the thin inner layer of the uterus known as the endometrium. This is the layer that breaks down every month during menstruation commonly known as a period - and that supports a baby during pregnancy.1 These changes are carefully controlled by the release of the hormones oestrogen and progesterone.

Endometrial hyperplasia most commonly develops after menopause, when the body stops making progesterone, though it can also take place around the time of menopause when ovulation is not as frequent.2 Endometrial hyperplasia can also result from other causes of imbalance between oestrogen and progesterone, such as medication that are similar to oestrogen, oestrogen therapy without progesterone, or irregular periods. 

If left untreated, endometrial hyperplasia may eventually lead to endometrial cancer, also known as uterine or womb cancer. For this reason it is important that you get checked as soon as possible to ensure that there is sufficient time to act upon the diagnosis. 

Types of endometrial hyperplasia

There are multiple classifications for endometrial hyperplasia, though they are usually based on how cells look and how likely it is to become cancer.3 The most updated classification divides endometrial hyperplasia into:2

  • Endometrial hyperplasia without atypia
  • Atypical endometrial hyperplasia 

You may also see endometrial hyperplasia being described as either simple hyperplasia or complex hyperplasia. This refers to how irregular and crowded the glands look. Glands are a type of structure found in the endometrium. 

Endometrial hyperplasia is sometimes classified as:4

  • Benign endometrial hyperplasia: there are changes to the cells of the lining but they are not cancerous
  • Endometrial intraepithelial neoplasia (EIN): changes in the uterine lining that are precancerous, meaning that they are in the process of becoming cancerous
  • Endometrial adenocarcinoma: changes to the lining that are cancerous 

Causes of endometrial hyperplasia

Endometrial hyperplasia results from an imbalance between oestrogen and progesterone. Made by the ovaries, these are the hormones that coordinate the uterine lining to grow and shed throughout the menstrual cycle. Endometrial hyperplasia is specifically the result of excessive oestrogen, what is generally referred to as unopposed oestrogen. This imbalance can have different causes:2

  • Menopause: following menopause, progesterone is no longer made 
  • Medications similar to oestrogen, such as tamoxifen 
  • Oestrogen hormone therapy without taking progesterone or progestin if you still has your uterus
  • Irregular periods, which may be a result of polycystic ovary syndrome (PCOS) or infertility
  • Obesity  

Signs and symptoms of endometrial hyperplasia

The most common symptom of endometrial hyperplasia is abnormal vaginal bleeding.4 This includes postmenopausal bleeding or periods that are heavier or longer than normal. If you have endometrial hyperplasia you may also experience menstruation cycles that last less than 21 days.

Please refer to your doctor if you experience any of these symptoms. An early diagnosis can increase the chance of successfully addressing the issue and reducing the risk of complications. 

Management and treatment for endometrial hyperplasia

There are different treatment options for endometrial hyperplasia depending on the type and whether you are planning to have children in the future.2

Treatment of endometrial hyperplasia without atypia

If you have endometrial hyperplasia without atypia, the risk of you developing uterine cancer over the next 20 years is less than 1 in 20 and it is likely that the abnormal cells found in the womb lining will return to normal without intervention. 

With this type of endometrial hyperplasia, any treatment will involve hormone treatment, specifically progesterone. It may be given as:

  • A progestin-containing intrauterine system (IUS), a type of coil commonly used as a contraceptive. It is inserted inside the uterus and releases progesterone to reduce the thickness of the womb. This treatment option is the most effective and has the fewest side effects
  • Progesterone tablets, usually prescribed for at least half a year to be taken every day

Progesterone treatment has been shown to be highly effective in addressing endometrial hyperplasia without atypia. It is estimated that 9 out of 10 people experience an improvement of the condition.3

If progesterone treatment is not suitable for you, your doctor may recommend observation and another biopsy to be conducted after 6 months from the first one.

In both cases, you will be asked to come back for a follow up biopsy after 6 months and 12 months. Once you have tested negative in two biopsies, you may be discharged. 

Treatment of atypical endometrial hyperplasia 

If you have atypical endometrial hyperplasia, you are at higher risk of developing womb cancer. For this reason, your doctor may discuss with you the possibility of performing a hysterectomy. During a hysterectomy, your uterus is removed, so you should only agree to it if you do not wish to have children. Complications of hysterectomy include heavy bleeding, infection, and damage to your bladder or bowel. 

Diagnosis of endometrial hyperplasia

If you have abnormal uterine bleeding and you are at least 35, or if you are 35 or younger and medication has not stopped the abnormal bleeding, your doctor may suggest some tests to detect endometrial abnormalities such as hyperplasia and cancer. These usually include:2,4

  • Transvaginal ultrasound: this is done by placing a small device in your vagina that measures how thick your endometrium is through soundwaves
  • Endometrial biopsy: this is the only way to truly diagnose endometrial hyperplasia. It involves taking a small sample of endometrial tissue by inserting a tube through your cervix to reach the uterus. Alternatives include hysteroscopy and a procedure known as dilation and curettage (D&C)

Risk factors

There are many factors that have been identified as increasing the risk of developing endometrial hyperplasia, including:2

  • Being 35 or older: endometrial hyperplasia without atypia is most common in people aged 50 to 54, while atypical hyperplasia is most common in people aged 60 to 64 [StatPearls
  • Never having been pregnant (nulliparity)
  • Reaching menopause at an older age
  • Beginning to menstruate at an earlier age
  • History of conditions, such as diabetes mellitus, polycystic ovary syndrome (PCOS), gallbladder disease, or thyroid disease
  • Obesity
  • Smoking
  • Family history of ovarian, colon, or uterine cancer


If left untreated, endometrial hyperplasia may eventually develop into cancer. This is a process that normally takes place over the course of several years, starting from thickening of the endometrium and the development of glands and eventually resulting in changes to cells.1

If you have atypical endometrial hyperplasia, you have a higher risk of uterine cancer. It is estimated that hyperplasia with atypia has a more than one in four risk of progressing into cancer if not treated in time.3 Talk to your doctor about available treatment options to reduce your risk of developing cancer. 


How can I prevent endometrial hyperplasia

Preventing endometrial hyperplasia involves addressing the causes behind your specific case, such as:2,4

  • Taking the prescribed dose of oestrogen and progesterone if you are being treated with hormone replacement therapy. Your doctor may prescribe a higher dose of progesterone if needed
  • Make sure your doctor knows if you are taking other medicines that are similar to oestrogen, such as medicines that address symptoms of menopause
  • Let your doctor know if you are taking tamoxifen
  • If you are overweight, losing weight may decrease your risk of developing endometrial hyperplasia

How common is endometrial hyperplasia

Endometrial hyperplasia is rare. It is estimated that around 133 every 100,000 is diagnosed with endometrial hyperplasia every year.5 

When should I see a doctor

Please see a doctor if you are experiencing abnormal vaginal bleeding, such as bleeding after menopause or unusually heavy periods. Your doctor may arrange some tests to identify the cause of your symptoms. 


Endometrial hyperplasia is a rare condition involving thickening of the uterine lining, leading to abnormal bleeding, formation of glands in the thickened uterus and, in some cases, cancer. If detected early, it can be treated with either hormone treatment or surgery, relieving symptoms and potentially avoiding complications. 


  1. Endometrial Hyperplasia [Internet]. Atlanta Gynecologic Oncology. 2023 [cited 5 May 2023]. Available from: https://atlantagynonc.com/conditions/endometrial-hyperplasia 
  2. Endometrial Hyperplasia [Internet]. NHS Foundation Trust. 2020 [cited 5 May 2023]. Available from: https://www.wuth.nhs.uk/media/18102/pl1003-endometrial-hyperplasia.pdf 
  3. Singh G, Puckett Y. Endometrial Hyperplasia. StatPearls. 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560693/    
  4. Endometrial Hyperplasia [Internet]. The American College of Obstetricians and Gynecologists. 2022 [cited 5 May 2023]. Available from: https://www.acog.org/womens-health/faqs/endometrial-hyperplasia 
  5. Reed SD, Newton KM, Clinton WL, Epplein M, Garcia R, Allison K, Voigt LF, Weiss NS. Incidence of endometrial hyperplasia. Am J Obstet Gynecol. 2009;200(6):678.e1-6. Available from: https://www.ajog.org/article/S0002-9378(09)00223-3/fulltext  
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Jose Jerez Pombo

Bachelor of Science - BSc, Biochemistry, King's College London logo

José has worked in the field of health and healthcare in a variety of settings ranging from international organisations and NGOs to CROs. He is currently an advisor at the Copenhagen Institute for Futures Studies (CIFS), participating in a wide variety of projects that seek to promote sustainable, equitable, and effective health systems and foster responsible and effective innovation in the health sector. José’s background is in biomedical science (specifically biochemistry) and global health.

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