Adenomyosis occurs when the endometrial tissue that normally lines the uterus grows into the muscular wall of the uterus (the myometrium). This causes the uterine muscle to thicken, swell, and bleed each month — resulting in an enlarged, tender uterus and often debilitating periods.
It's more common than most people realise — estimated to affect up to 20–35% of women of reproductive age — yet it often takes years to diagnose and is frequently dismissed as "just heavy periods."
Adenomyosis Symptoms
Symptoms vary considerably in severity. Some women have minimal symptoms; others find adenomyosis significantly impacts their quality of life. Common symptoms include:
Heavy menstrual bleeding
Menorrhagia (heavy periods) is the most common symptom — soaking through protection, passing large clots, anaemia from blood loss. Periods are often prolonged (7+ days).
Severe period pain
Dysmenorrhoea (painful periods) that doesn't respond well to standard pain relief — often described as a deep, cramping ache that radiates to the lower back and thighs.
Chronic pelvic pain
Pain that persists throughout the month, not just during periods. Can be a constant dull ache or episodic stabbing pains.
Painful sex
Dyspareunia (pain during or after sex), particularly deep penetration, is common. The uterus is often tender to touch.
Enlarged, "boggy" uterus
The uterus is often enlarged and tender on examination — a doctor may describe it as "bulky" or "boggy."
Spotting between periods
Some women experience irregular bleeding or spotting at times other than their period.
How Adenomyosis Differs from Endometriosis
Adenomyosis and endometriosis are related but distinct conditions — and many women have both:
- Location: In endometriosis, tissue similar to the endometrium grows outside the uterus (on the ovaries, tubes, bowel, bladder). In adenomyosis, it grows within the uterine muscle.
- Symptoms: Adenomyosis more commonly causes heavy bleeding and an enlarged uterus. Endometriosis more commonly causes infertility and bowel/bladder symptoms. Pain is prominent in both.
- Diagnosis: Endometriosis requires laparoscopy for definitive diagnosis. Adenomyosis can often be seen on MRI or, in skilled hands, on ultrasound.
- Treatment: Treatments overlap but the surgical approach differs — endometriosis requires excision of lesions; adenomyosis affecting the whole uterus is not surgically curative short of hysterectomy.
Adenomyosis has historically required hysterectomy for diagnosis (it can only be confirmed on pathology). However, MRI and specialist transvaginal ultrasound by an experienced sonographer can now diagnose it in most cases without surgery. If you're struggling with heavy, painful periods, ask specifically about adenomyosis — it may not be on the differential if you don't raise it.
Treatment Options for Adenomyosis
Treatment depends on your symptoms, age, and whether you want to preserve fertility:
- Hormonal contraception — the combined pill, progesterone-only pill, or hormonal IUD (Mirena) can significantly reduce bleeding and pain by suppressing the endometrium. The Mirena IUD often provides substantial symptom relief and is a good first-line option.
- GnRH agonists — medications like Prostap or Zoladex create a temporary menopause, which significantly reduces symptoms. Used for limited periods (usually 3–6 months) due to bone density effects; add-back HRT mitigates side effects.
- Anti-inflammatory pain relief — NSAIDs (ibuprofen, mefenamic acid) reduce prostaglandin-driven pain and can decrease bleeding. Most effective when started 1–2 days before the period begins.
- Uterine artery embolisation (UAE) — a minimally invasive procedure that reduces blood supply to the uterus. Can significantly reduce bleeding and pain; not recommended if future pregnancy is desired.
- Hysterectomy — the only definitive cure. Considered when symptoms are severe, fertility is not a priority, and other treatments have failed.
Adenomyosis and Fertility
Adenomyosis can affect fertility by disrupting implantation and uterine receptivity. Research suggests it may reduce IVF success rates if untreated. However, many women with adenomyosis conceive naturally, and treatment (particularly with a Mirena IUD for several months before trying to conceive) may improve outcomes. Discuss your individual case with a specialist who has experience in both adenomyosis and fertility.
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