What is adenomyosis?

Adenomyosis is a condition where the tissue that normally lines the uterus grows into the muscular wall of the uterus. This causes the uterus to enlarge and can lead to heavy, painful periods and pelvic pressure.

Unlike endometriosis, which occurs outside the uterus, adenomyosis occurs within the uterus itself. The two conditions can coexist — many women have both.

How are they different?

Endometriosis can occur anywhere in the pelvis — on the ovaries, fallopian tubes, bowel, or bladder. Adenomyosis is confined to the uterine muscle. Endometriosis is diagnosed surgically, while adenomyosis can often be diagnosed through imaging (MRI or ultrasound).

The symptoms overlap significantly: both cause pain and heavy bleeding. However, adenomyosis tends to cause an enlarged, tender uterus, while endometriosis may cause pain throughout the cycle, including during sex and bowel movements.

Treatment differences

Treatment approaches differ. Endometriosis is often treated with laparoscopic surgery and hormonal therapy. Adenomyosis may be managed with hormonal treatments (including a hormonal IUD), and in severe cases, a hysterectomy may be considered.

Your GP can help determine which condition — or both — may be causing your symptoms and arrange the appropriate investigations and referrals.

Related condition

Endometriosis →

References & sources