🔑 Key Learning

• Dysmenorrhoea = menstruation-related abdominal pain.
• Primary dysmenorrhoea = no underlying pelvic pathology (common in adolescents).
  • First-line management is NSAIDs; COCP can be considered if contraception is acceptable.
• Secondary dysmenorrhoea = associated with pathology (endometriosis, adenomyosis, PID, fibroids).
• Always exclude pathology before diagnosing primary dysmenorrhoea.

🧬 Pathophysiology

• Primary dysmenorrhoea: excessive prostaglandin release causing painful uterine contractions.
• Secondary dysmenorrhoea: pain due to underlying structural or inflammatory pelvic pathology.

👀 Clinical Features

Primary Dysmenorrhoea

• Cramping lower abdominal pain starting just before menstruation and lasting 2–3 days.
• Typically begins around 6 months after menarche.
• No associated gynaecological symptoms.

Secondary Dysmenorrhoea

• Painful periods previously absent or now different in character.
• Pain starts 3–4 days before menstruation and may continue after.
• Other gynaecological symptoms: vaginal discharge, bleeding, dyspareunia, menorrhagia.
• Suggestive of endometriosis, adenomyosis, PID, fibroids.

🧪 Investigations

• Pelvic ultrasound to identify fibroids, adenomyosis, endometriosis.
• High vaginal/endocervical swabs to exclude STIs.
• Pregnancy test to exclude pregnancy-related causes.

💊 Management of Primary Dysmenorrhoea

Step 1

• 1st line: NSAIDs (ibuprofen, naproxen, mefenamic acid).
• Alternative 1st line if not trying to conceive: Hormonal contraception (e.g. COCP) for 3–6 months if contraception is acceptable.
• Add paracetamol if required, or use paracetamol alone if NSAIDs contraindicated.
• If treatment is ineffective: Combine NSAID + hormonal contraception

Step 2

• Combination of NSAID (or paracetamol) + COCP.

💥 Management of Secondary Dysmenorrhoea

• Management depends on underlying cause (refer to specific condition notes).

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🩸 Endometriosis

🧬 Pathophysiology

• Endometrium-like tissue outside the uterine cavity (commonly pelvis).
• Tissue bleeds, causing inflammation and scar tissue formation in response to menstrual cycle hormones.

👀 Clinical Features

• Secondary dysmenorrhoea.
• Chronic pelvic pain.
• Deep dyspareunia.
• Subfertility or infertility.
• Bowel symptoms (e.g. pain on defecation).

🧪 Investigations

• Laparoscopy is gold standard for definitive diagnosis (classic finding: ‘chocolate cysts’ or endometriomas).
• TVUS/TAUS may be supportive.

💊 Management

• Refer for specialist assessment.
• Pain management:
  • Trial of paracetamol and/or NSAID.
  • Hormonal therapy: COCP, POP, implant, Mirena IUS, or depot injections.
• Surgery in secondary care if medical management fails.

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🩺 Adenomyosis

🧬 Pathophysiology

• Extension of endometrial tissue into uterine myometrium.

👀 Clinical Features

• Menorrhagia.
• Irregular periods.
• Dysmenorrhoea.

🧪 Diagnosis

• MRI pelvis: enlarged uterus with thickened myometrium.

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🔗 Useful Links and References

NICE CKS. Dysmenorrhoea [Last revised October 2023].