Adenomyosis: Symptoms, Diagnosis and Treatment

Adenomyosis is a condition where the lining of the womb grows into the muscle of the womb wall. It can cause painful, heavy periods, pelvic pain and pain during sex, though some women have no symptoms at all. Its cause is not clear, and treatments range from a hormonal coil and other medicines to surgery.

What is adenomyosis?

The NHS describes it as a condition where the lining of the womb (uterus) starts growing into the muscle in the wall of the womb. ACOG uses almost the same words: tissue that normally lines the uterus begins to grow in the muscle wall of the uterus.

How is adenomyosis different from endometriosis?

The names sound alike and the symptoms overlap, but they are different conditions. The NHS explains that in endometriosis, tissue similar to the lining of the womb grows in other places, such as the ovaries or fallopian tubes. In adenomyosis it grows into the wall of the womb itself.

A 2026 systematic review describes them as ultimately distinct diseases with different pathophysiological mechanisms, and notes that women often have both conditions simultaneously (Koroneos et al., 2026). The NHS lists adenomyosis among the conditions whose symptoms can be similar to endometriosis, which is part of why it can take several tests to tell them apart.

What are the symptoms of adenomyosis?

The NHS lists symptoms that affect your periods:

• painful periods, where the pain may be severe and stop you from doing your usual activities
• heavy bleeding during your period

And symptoms that can happen any time in your menstrual cycle:

• pelvic pain (pain in the lower part of your tummy)
• bloating, heaviness or fullness in your tummy
• pain during sex

ACOG says signs may include heavy menstrual bleeding and menstrual pain that worsens with age. And the NHS says some people with adenomyosis have no symptoms.

How do I know if my periods count as heavy?

ACOG lists signs of heavy menstrual bleeding, including bleeding that lasts more than 7 days, soaking through one or more pads or tampons every hour for several hours in a row, needing to wear more than one pad at a time, needing to change pads or tampons during the night, and clots as big as a US quarter coin or larger. ACOG names adenomyosis among the causes of heavy menstrual bleeding, and warns that heavy blood loss can lead to iron-deficiency anemia.

Who gets adenomyosis?

The NHS says it is more commonly diagnosed in women over the age of 30 and can affect anyone who has periods. ACOG says it is more common in older women who have had children.

What causes it is not known. The NHS says it's not clear what causes adenomyosis, and that you may be more likely to get it if you are over the age of 30 and have given birth.

How common is adenomyosis?

Nobody has a single clear figure, and it depends heavily on who is being counted. A 2025 systematic review and meta-analysis pooled 59 studies on adenomyosis. It estimated 1% in the general population worldwide, but 41% to 49% among patients experiencing gynaecologic symptoms (Wang et al., 2025). The gap between those numbers is the honest answer: among women who already have gynaecological symptoms, it turns up far more often than in the population as a whole.

How is adenomyosis diagnosed?

The NHS says a GP may ask about your periods and feel your tummy to see if there's any swelling or bloating, and might ask to do an internal examination.

Two things the NHS spells out that are worth knowing before you go:

• you can ask for a female doctor when you book your appointment
• you can have a friend, family member or other member of staff in the room with you during your examination if you want

Further tests may include an ultrasound scan or an MRI scan, sometimes to rule out similar conditions such as endometriosis.

What are the treatments for adenomyosis?

The NHS lists:

• the IUS (intrauterine system, also called Mirena or hormonal coil), which thins the womb lining, making your periods lighter and less painful
• other hormonal contraception if you cannot or do not want to have an IUS, such as the progestogen-only pill, the combined pill or the contraceptive patch
• medicines such as tranexamic acid or NSAIDs

ACOG similarly mentions NSAIDs, a birth control method, or other medications, and adds that uterine artery embolization (UAE) also can be done to treat adenomyosis.

If these do not work, the NHS says surgery may be needed: a hysterectomy, or surgery to remove the lining of your womb (endometrial ablation). ACOG says hysterectomy for adenomyosis usually is a last resort, done when other treatments have not worked. After the womb is removed, a woman can no longer get pregnant and will no longer have periods.

What does the research say about which medicine works best?

Not much yet, and that is worth saying plainly. A 2026 meta-analysis compared the hormonal coil with a medicine called dienogest and found no significant differences in period pain, uterine volume, or menstrual blood loss at 3 and 6 months. It included only 8 studies, and its authors called for larger randomised trials to build evidence-based treatment plans (Su et al., 2026). In practice, the choice is made with your doctor around your symptoms and what you can live with.

Does adenomyosis affect fertility?

The sources here say less than you might hope. The 2026 review on women who have both adenomyosis and endometriosis found that clinical pregnancy rates and live birth rates were significantly reduced in that group, but results for other pregnancy outcomes were inconsistent. If you are planning a pregnancy, raise it with your doctor before choosing a treatment, since some, like hysterectomy, end the possibility.

What can I do at home for adenomyosis pain?

The NHS suggests:

• a heat pad or hot water bottle wrapped in a tea towel on your tummy
• a TENS machine, a small device that uses mild electrical impulses to reduce pain
• painkillers like paracetamol or ibuprofen

When should I see a doctor?

Ask for an urgent GP appointment or get help from NHS 111 if your pelvic pain or period pain is severe or worse than usual, and painkillers have not helped.

See a GP if:

• your periods become more painful, heavier or irregular
• you have pain during sex
• heavy periods are affecting your life or you've had them for some time
• you've been feeling bloated for a while (about 3 weeks)
• you bleed between periods or after sex

The short version

Adenomyosis is when the womb lining grows into the womb's own muscle wall, and it can cause painful, heavy periods, pelvic pain and pain during sex, or no symptoms at all. It is diagnosed more often in women over 30 who have given birth, and its cause is not clear. It is a separate condition from endometriosis, though many women have both. Treatment starts with options like the hormonal coil, other hormonal contraception and anti-inflammatory medicines, with surgery if those do not help.

Sources

• NHS, Adenomyosis - definition, symptoms, who gets it, GP appointment, tests, treatments, self-care, when to see a GP.
• NHS, Endometriosis - adenomyosis listed as a condition with similar symptoms.
• ACOG, Dysmenorrhea: Painful Periods FAQ - definition, who it is more common in, NSAIDs, birth control, UAE, hysterectomy as last resort.
• ACOG, Abnormal Uterine Bleeding FAQ - heavy bleeding and pain that worsens with age, effects of hysterectomy.
• ACOG, Heavy Menstrual Bleeding FAQ - signs of heavy bleeding, adenomyosis as a cause, anemia.
• Wang et al., 2025, Global prevalence of adenomyosis and endometriosis: a systematic review and meta-analysis - prevalence estimates in different groups.
• Su et al., 2026, Levonorgestrel-releasing intrauterine device versus dienogest for adenomyosis: systematic review with meta-analysis - comparison of two treatments and the limits of the evidence.
• Koroneos et al., 2026, Comorbidity of endometriosis and adenomyosis: a systematic review - distinct conditions, often together, fertility findings.

This article describes what those sources say. It is not medical advice, and it is not a substitute for a doctor, nurse or pharmacist.