How can I differentiate between adenomyosis and other causes of dysmenorrhea in my patients?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Differentiating adenomyosis from other causes of dysmenorrhea involves a combination of clinical assessment and targeted imaging investigations. Clinically, adenomyosis often presents with heavy menstrual bleeding and significant dysmenorrhea, sometimes accompanied by a bulky, tender uterus on pelvic examination, which can help distinguish it from other causes such as endometriosis or fibroids .

Initial assessment should include a detailed menstrual and pain history, focusing on the severity and impact of dysmenorrhea, and a pelvic examination to detect uterine enlargement or tenderness suggestive of adenomyosis ,. Unlike endometriosis, which may present with cyclical pelvic pain, deep dyspareunia, and bowel or urinary symptoms, adenomyosis symptoms are more centered on uterine-related pain and bleeding .

Transvaginal ultrasound is the preferred first-line imaging modality to evaluate suspected adenomyosis, especially in women with heavy menstrual bleeding and dysmenorrhea or a bulky uterus on examination . Ultrasound features suggestive of adenomyosis include a heterogeneous myometrium, myometrial cysts, and asymmetrical thickening of the uterine walls [].

While MRI can be used for further assessment, especially in complex cases, transvaginal ultrasound remains the practical and accessible choice in general practice []. It is important to note that adenomyosis can coexist with other pathologies such as fibroids or endometriosis, so a comprehensive assessment is essential [].

Serum CA125 is not recommended for diagnosis, and definitive diagnosis may require specialist imaging or histopathology, but initial differentiation relies heavily on clinical features and ultrasound findings ,.

In summary, to differentiate adenomyosis from other causes of dysmenorrhea:

  • Take a thorough history emphasizing heavy menstrual bleeding and uterine pain.
  • Perform pelvic examination to assess for uterine enlargement and tenderness.
  • Offer transvaginal ultrasound to identify characteristic myometrial changes.
  • Consider referral for specialist imaging or gynaecology assessment if diagnosis remains unclear or symptoms are severe ,.

Educational content only. Always verify information and use clinical judgement.