Adenomyosis vs. Endometriosis

Carrie Madormo, RN, MPH
·7 min read

Both affect the lining of the uterus, but have distinct differences

Medically reviewed by Cordelia Nwankwo, MD

Adenomyosis and endometriosis are medical conditions that cause an overgrowth of the lining of the uterus (endometrium). With adenomyosis, the tissue grows into the walls of the uterus. With endometriosis, the tissues grow outside of the uterus and can extend to the ovaries, fallopian tubes, pelvic wall, and bowel.

Although they are two distinct conditions, adenomyosis and endometriosis share symptoms such as painful periods and heavy menstrual bleeding. Because of this, they are often mistaken for one another. They can even occur at the same time.

This article describes the symptoms and causes of adenomyosis and endometriosis and explains how the two conditions are diagnosed and treated.

<p>Bernie_Photo / Getty Images</p>

Bernie_Photo / Getty Images



A Note on Gender and Sex Terminology

Verywell Health acknowledges that sex and gender are related concepts, but they are not the same.

  • Sex refers to biology: chromosomal makeup, hormones, and anatomy. People are most often assigned male or female at birth based on their external anatomy; some people do not fit into that sex binary and are intersex.

  • Gender describes a person's internal sense of self as a woman, man, nonbinary person, or another gender, and the associated social and cultural ideas about roles, behaviors, expressions, and characteristics.

Research studies sometimes don't use the terminology in this way. For example, terms that describe gender (“woman,” “man”) may be used when terms for sex (“female,” “male”) are more appropriate. 

To reflect our sources accurately, this article uses terms like "female," "male," "woman," and "man" as the sources use them.



Tissue Growth in Adenomyosis vs. Endometriosis

Adenomyosis involves cells of the endometrium extending into the walls of the uterus (myometrium), causing them to thicken.

Despite these changes, the endometrial tissues remain functional and are shed with each period, causing bleeding.

The tissues that extend beyond the uterus in endometriosis are different. While they are similar to endometrial tissue, they are not exactly like what's in the uterus.

These tissues function similarly—breaking down and bleeding with each period—but ultimately become trapped in the organs they invade. This can lead to scarring and adhesions (the sticking together of tissues).

Symptoms of Adenomyosis and Endometriosis

Despite being two separate conditions, adenomyosis and endometriosis share many of the same symptoms, including heavy menstrual bleeding and painful periods. Even so, there are certain signs that can help differentiate them.

Adenomyosis Symptoms

  • Heavy menstrual bleeding

  • Painful menstrual periods

  • Painful sexual intercourse

  • Enlarged uterus

Endometriosis Symptoms

  • Heavy menstrual bleeding

  • Painful menstrual periods

  • Painful sexual intercourse

  • Spotting or bleeding between periods

  • Infertility

  • Pain with bowel movements or urination

  • Digestive problems

  • Fatigue

Comparatively, though, endometriosis causes more symptoms than adenomyosis. In some cases, people with adenomyosis may have no symptoms at all and only find out about their condition when it is advanced or diagnosed along with endometriosis.

Learn More: How to Manage Endometriosis Pain

Causes

The exact cause of adenomyosis and endometriosis is unknown. However, certain risk factors can increase the likelihood of developing these conditions.

Broadly speaking, adenomyosis is associated with prior or ongoing stress placed on the uterus. Endometriosis is influenced by genetics and other conditions that interfere with normal menstrual cycles.

Around 10% of females of reproductive age are affected by endometriosis. While it is harder to determine the prevalence of adenomyosis because it is often asymptomatic, studies suggest that the condition may affect about 20% of females of reproductive age. 

Additionally, rates of endometriosis in transgender men are higher than those experienced by cisgender females and need to be considered.

Adenomyosis Risk Factors

Endometriosis Risk Factors

  • Being in your 30s or 40s

  • Having never had children

  • Having short menstrual cycles (less than 27 days)

  • Heavy menstrual periods that last for more than seven days

  • A family history of endometriosis

  • Menstruation starting before age 11

Learn More: How Do Endometriosis Symptoms Feel?

Diagnosing Adenomyosis vs. Endometriosis

Adenomyosis and endometriosis are diagnosed with many of the same tools and techniques, including:

There are also other diagnostic tools used specifically for adenomyosis or endometriosis.

Identifying Adenomyosis

The only way to truly diagnose adenomyosis is to examine the tissue of the uterus after a hysterectomy, surgery to remove the uterus. The decision to undergo a hysterectomy is based on a review of the benefits and risks of the procedure.

In some instances, your healthcare provider may perform a biopsy to obtain a sample of the endometrium that can be examined under a microscope. But this is done to ensure that a more serious condition like uterine cancer or endometrial cancer isn't involved—not to aid in the diagnosis of adenomyosis.

Identifying Endometriosis

In some cases, your healthcare provider will refer you to a surgeon to undergo a laparoscopy. This is a surgical procedure in which a tube-like scope is inserted through a tiny incision in the abdomen to view the pelvic organs.

Laparoscopy can provide details about the size, location, and extent of the spread of endometrial tissues outside of the uterus. Your surgeon may also take an endometrial biopsy for further testing.

Learn More: How Endometriosis Is Treated

Treatment Options

Treatment for adenomyosis and endometriosis varies based on which symptoms are present and how severe they are. While there is no cure for these conditions, they can be well-managed.

Among some of the treatment options commonly used for both conditions are:

Other treatments used specifically for endometriosis include:

Learn More: Adenomyosis and Hysterectomy

Living With Adenomyosis or Endometriosis

Living with chronic pain from adenomyosis or endometriosis can be distressing and 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 2016 study reported that women with endometriosis found it helpful to plan work and social events around their menstrual periods. This is to avoid being active during the heaviest days of their periods, when pain is the most intense.

Other coping techniques for endometriosis include:

Summary

Adenomyosis and endometriosis are chronic conditions that affect the endometrium, the tissue lining of the uterus. They differ in that the former involves tissue growth into the muscular wall of the uterus, while the latter involves tissue growth outside of the uterus into surrounding organs.

Symptoms of both include pelvic pain and heavy menstrual periods, but there are some unique symptoms as well. Possible treatments include over-the-counter pain relievers, hormonal contraceptives, and hysterectomy.

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. The uterus can become enlarged when its walls become overly thick due to endometrial tissue growth. This can cause the abdomen to swell.

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.

Read the original article on Verywell Health.