Adenomyosis vs. Endometriosis: What Are the Differences?

Endometriosis and adenomyosis affect the lining of the uterus (endometrium). The uterus is the organ where a baby grows when a person is pregnant. 

In endometriosis, endometrial tissue grows outside of the uterus. In adenomyosis, endometrial tissue grows into the muscular walls of the uterus. Although they are different conditions, both can lead to painful menstrual periods.

Because they share similar symptoms, adenomyosis and endometriosis are sometimes mistaken for one another. One study found that adenomyosis is more commonly found in women with endometriosis than in those without it.

This article provides an overview of both conditions, common symptoms, and treatments.

Shot of a young woman suffering from stomach cramps at home

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What Is Adenomyosis?

Adenomyosis is a condition that causes a thickening of the uterine walls. Adenomyosis occurs when endometrial tissue typically found inside the uterus grows into the outer muscular walls of the uterus. This tissue usually makes up the inner lining of the uterine walls. When it extends into the outer muscular layer, it leads to a thickening of the uterine walls. 

What Is Endometriosis? 

Endometriosis is a condition that occurs when endometrial tissue grows outside of the uterus. These growths of endometrial tissue may be referred to as lesions, nodules, or implants. This tissue can grow behind the uterus or on surrounding tissues such as the ovaries, fallopian tubes, bowels, or bladder. Rarely does endometrial tissue grow into distant areas of the body, such as the lungs. 

How Common Are Adenomyosis and Endometriosis?

About 10% of women and girls of reproductive age are affected by endometriosis. It is more difficult to determine the prevalence of adenomyosis because it often does not cause symptoms. A study found that adenomyosis may affect about 20% of women and girls of reproductive age. 

Symptoms 

Adenomyosis and endometriosis share some of the same symptoms. However, it is possible to tell them apart. In general, endometriosis causes more symptoms. Many individuals with adenomyosis may not be aware of it because of the lack of symptoms.

Symptoms of Adenomyosis and Endometriosis

Adenomyosis
  • Heavy menstrual bleeding

  • Painful menstrual periods

  • Painful sexual intercourse

  • Enlarged uterus

Endometriosis
  • Heavy menstrual bleeding

  • Painful menstrual periods

  • Painful sexual intercourse

  • Spotting or bleeding between periods

  • Infertility

  • Pain with bowel movements or urination

  • Digestive problems

  • Fatigue

Causes 

In both adenomyosis and endometriosis, the exact cause is unknown. However, risk factors may increase the likelihood of being diagnosed with one of these conditions. 

Risk Factors 

Women age 35–50 who have had at least one pregnancy have an increased chance of developing adenomyosis.

Risk factors of endometriosis include:

The risk of endometriosis may be lower if you have been pregnant and/or breastfed in the past. 

Diagnosis

If you have developed any symptoms of adenomyosis or endometriosis, it’s important to see your healthcare provider. 

Adenomyosis

The only way to truly diagnose adenomyosis is by examining the tissue of the uterus after a hysterectomy. A hysterectomy is a surgery done to remove the uterus. 

Your healthcare provider will begin with a thorough history and physical exam to determine if you have adenomyosis without performing a hysterectomy. It may be helpful to keep a log of your symptoms and when they occur, which can help determine the correct diagnosis. 

Your healthcare provider will likely perform a pelvic exam to check if the uterus feels enlarged. An ultrasound of the uterus can also show if the organ is enlarged. An MRI (magnetic resonance imaging) of the uterus may be done to rule out other causes of symptoms, such as a tumor. 

Endometriosis

As with adenomyosis, the diagnosis of endometriosis usually begins with a physical exam and medical history. If your healthcare provider suspects endometriosis, they will likely perform a pelvic exam and order imaging tests. 

Endometriosis can be diagnosed with laparoscopy, a surgery that involves inserting a thin tube into the lower abdomen through a small cut in the skin. This tube, known as a laparoscope, has a camera and a light on the end of it. The healthcare provider can determine if you have endometriosis based on where endometrial tissue is found. A biopsy of the tissue may be taken as well. 

Treatment 

Treatment for both adenomyosis and endometriosis varies based on which symptoms are present and how severe they are. 

Adenomyosis

Most individuals with adenomyosis do not require treatment. If you are experiencing symptoms such as heavy or painful menstrual periods, your healthcare provider may recommend oral birth control or an intrauterine device (IUD). Birth control treatments that contain progesterone can help to decrease the amount of menstrual bleeding.

Over-the-counter (OTC) pain medications like Advil or Motrin (ibuprofen) may help to relieve the pain associated with heavy menstrual bleeding. If your symptoms are severe, your healthcare provider may discuss a hysterectomy with you. 

Endometriosis

There is no cure for endometriosis, and treatment is provided to manage the symptoms. OTC pain relievers like Advil or Motrin can be taken to relieve menstrual pain. For more severe pain, your healthcare provider may prescribe a pain medication to be used as needed.

Oral birth control pills and other hormone treatments can also help relieve endometriosis symptoms. To slow the growth of endometrial tissue, your provider may recommend treatment with gonadotropin-releasing hormone (GnRH) agonists. It’s important to note that these medications cause temporary menopause.

If your symptoms are severe, your provider may recommend surgery to remove the patches of extra endometrial tissue. This may be done through a laparoscopy or may require surgery.

Infertility caused by endometriosis can be treated with medical interventions, such as:


When to See a Healthcare Provider

See your healthcare provider if you develop any symptoms of adenomyosis or endometriosis. While there is no cure for these conditions, the symptoms can be well-managed with treatment. 

Living With Adenomyosis or Endometriosis 

Living with chronic pain from endometriosis or adenomyosis is distressing and can lead to feelings of depression or anxiety. If you are concerned about your mood, ask your healthcare provider for a referral to a mental health professional such as a psychologist or therapist. 

A study found that women with endometriosis found it helpful to plan work and social events around their menstrual periods. This is to avoid being active when pain is the most intense during the heaviest days of their periods. 

Other coping techniques for endometriosis include: 

  • Dietary changes
  • Increased exercise
  • Meditation
  • Massage
  • Acupuncture 
  • Heating pad 

Summary

Adenomyosis and endometriosis are chronic conditions that affect the endometrium, the tissue that lines the walls of the uterus. In adenomyosis, endometrial tissue grows into the outer muscular walls of the uterus. In endometriosis, endometrial tissue grows outside of the uterus on surrounding tissues. Symptoms of both conditions may include pelvic pain and heavy menstrual periods. Possible treatment options include OTC pain medications and hormone therapy. 

A Word From Verywell 

Being diagnosed with adenomyosis or endometriosis can feel devastating. Both of these conditions may lead to intense pain and heavy bleeding. These symptoms can significantly influence your quality of life. Talk with your healthcare provider if you have developed any adenomyosis or endometriosis symptoms. There are treatments available that can help to alleviate your symptoms.

Frequently Asked Questions

  • Is adenomyosis more severe than endometriosis?

    Endometriosis is more likely to cause symptoms than adenomyosis. Many individuals with adenomyosis do not know they have it because of the lack of symptoms. 

  • Does adenomyosis cause abdominal distension?

    Adenomyosis may lead to abdominal distention because it can cause the uterus to become enlarged. This occurs when the walls of the uterus become overly thick due to the endometrium growing into the outer muscular walls of the uterus. 

  • Can adenomyosis turn to endometriosis?

    While adenomyosis does not cause endometriosis, the two conditions are linked. Individuals with endometriosis are more likely to be diagnosed with adenomyosis than women without a disorder of the endometrium.

  • What’s common between adenomyosis and endometriosis?

    Adenomyosis and endometriosis affect the lining of the uterus known as the endometrium. Both conditions may lead to pelvic pain and heavy menstrual bleeding.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. MedlinePlus. Adenomyosis.

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  4. World Health Organization. Endometriosis.

  5. Naftalin J, Hoo W, Pateman K, Mavrelos D, Holland T, Jurkovic D. How common is adenomyosis? A prospective study of prevalence using transvaginal ultrasound in a gynaecology clinic. Hum Reprod. 2012 Dec;27(12):3432-9. doi:10.1093/humrep/des332

  6. Laganà AS, La rosa VL, Rapisarda AMC, et al. Anxiety and depression in patients with endometriosis: impact and management challenges. Int J Womens Health. 2017;9:323-330. doi:10.2147/IJWH.S119729

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Additional Reading

By Carrie Madormo, RN, MPH
Carrie Madormo, RN, MPH, is a health writer with over a decade of experience working as a registered nurse. She has practiced in a variety of settings including pediatrics, oncology, chronic pain, and public health.