Adenomyosis vs. Endometriosis: What’s the Difference?

Content medically reviewed by Julia Vasquez Lopez, MD

Adenomyosis and endometriosis are two chronic gynecological conditions that cause mainly pain and menstrual irregularities, among other symptoms. It's easy to confuse them, as both involve tissue similar to the lining of the uterus. However, these distinct conditions affect different parts of the pelvic area.

The exact cause of the two conditions is not entirely known.

“A combination of factors, such as your genetic predisposition and hormones, could increase your risk for either adenomyosis or endometriosis,” said Dr. Julia Vasquez Lopez, an OB/GYN at Essentia Health. “Understanding the difference is crucial for proper diagnosis and treatment.”

What Is Endometriosis?

If you have endometriosis, endometrial tissue grows outside the uterus. These growths, called implants, grow on ovaries, fallopian tubes, the outer surface of the uterus, and in severe cases in other abdominal organs like the bowel and bladder.

Implants behave much like the tissue inside the uterus—they respond to hormonal changes in the menstrual cycle, bleeding, breaking down and bleeding. However, the blood has nowhere to go, leading to inflammation, scarring, adhesions and cysts.

Symptoms of Endometriosis

The most common symptom is pelvic pain, which often worsens during your period.Other symptoms include –

• Abdominal problems, including bloating, constipation and diarrhea
• Fatigue
• Fertility issues
• Pain during or after sex
• Painful bowel movements or urination

What Is Adenomyosis?

With adenomyosis, endometrial tissue grows into the muscular wall of the uterus, called the myometrium. The presence of this tissue within the uterine muscle causes the wall to thicken and often enlarges the entire uterus.

This misplaced tissue also responds to hormonal fluctuations during menstruation. As a result, it may bleed and cause inflammation within the uterine wall that leads to cramps and pain.

Symptoms of Adenomyosis

Heavy menstrual bleeding and painful menstrual cramps are two primary symptoms. Other symptoms include –

• Pelvic pain during menstruation and throughout your cycle
• Periods that last longer than usual
• Tender and enlarged uterus

3 Differences Between Adenomyosis and Endometriosis

1. Location

The main difference between adenomyosis and endometriosis is where the growth occurs. Endometriosis causes tissue to grow outside the uterus, while adenomyosis grows in the uterus muscle wall.

2. Symptoms

Both conditions have an overlap of symptoms, including lower abdominal pain, intense menstrual pain and heavy bleeding during periods.

However, adenomyosis can cause an enlarged and tender uterus. Endometriosis causes inflammation and scarring in the areas where the growths are happening, leading to pain that can be more varied depending on the affected organs.

3. Diagnostic Approaches

Imaging techniques like transvaginal ultrasound or MRI are commonly used to help diagnose adenomyosis. These scans can show if there’s thickening on the uterine wall.

Laparoscopy, a type of minimally invasive surgery, is required to diagnose endometriosis. Imaging can help diagnose signs of endometriosis, but laparoscopy is the only way to get an accurate diagnosis.

Treating Adenomyosis and Endometriosis

The treatment of adenomyosis and endometriosis aims to ease symptoms, including pain and heavy menstrual bleeding. Your treatment may also address infertility if you’re having trouble getting pregnant. There are some similarities in the treatment approaches, but they can also be specific to the condition.

“Often medical treatment is the same for adenomyosis and endometriosis,” Dr. Lopez said. “Ultimately, your condition, goals, and health status will determine the personalized treatment plan your provider recommends.”

Common treatment approaches

Hormonal therapies. These treatments help stop the growth of endometrial-like tissue. They include birth control pills, progestin-only pills, hormonal patches, GNRH antagonists, and intrauterine devices (IUDs).

Pain relief. Over-the-counter anti-inflammatory drugs (like ibuprofen or naproxen) can help manage pain. However, for severe pain, you may need stronger prescription pain relievers.

Nonhormonal medication like tranexamic acid can specifically help reduce heavy menstrual bleeding by helping blood to clot.

Pelvic floor therapy can also play an important role postoperatively in patients with definitive surgical treatment.

Endometriosis Treatments

Surgery to remove endometriosis implants is a common treatment, especially for severe pain or infertility. This is typically done via laparoscopy. However, medical treatment will often be needed after surgery, depending on the severity of endometriosis and if residual disease is suspected.

Adenomyosis Treatments

The only treatment that can cure adenomyosis is removing the uterus during a procedure called a hysterectomy. This may be recommended if your symptoms are severe and you do not plan to have children.

Getting Help

If you’re experiencing symptoms of either condition, it’s important to talk to your provider to get an accurate diagnosis. This is the first step to getting the best treatment to ease your symptoms, improve your quality of life—and help you get pregnant, if you’re trying to conceive.