Dysmenorrhea (Painful Periods)

🔍 When to Suspect

Cramping pain in the lower abdomen occurring just before or during a menstrual period, either from menarche (primary) or developing later in life (secondary)

From the full topic in The Ocean Library: Dysmenorrhea (Painful Periods)

🧭 When to suspect

Dysmenorrhoea is painful, cramping lower abdominal pain occurring just before or during menstruation, and is one of the commonest gynaecological presentations in primary care – around 1 in 10 women have pain severe enough to disrupt school, work or daily activities.

The single most useful clinical task is to separate primary dysmenorrhoea (no pelvic pathology; driven by excess endometrial prostaglandins) from secondary dysmenorrhoea (an underlying structural or inflammatory cause), because this changes investigation, treatment and referral. The discriminators are the age at onset relative to menarche and the pattern of the pain.

A practical rule: typical cyclical pain in a young woman with a normal examination needs no investigation and can be treated empirically; new, worsening, or non-cyclical pain, pain extending beyond menstruation, or any red-flag feature warrants examination and a search for a secondary cause.

Feature	Primary dysmenorrhoea	Secondary dysmenorrhoea
Onset	Typically 6–12 months after menarche, once cycles become ovulatory	Often years after menarche; new pain after previously pain-free or mild periods
Mechanism	Excess prostaglandins → uterine hypercontractility and ischaemia; no pelvic pathology	Underlying pathology – endometriosis, adenomyosis, fibroids, PID, ovarian pathology
Timing of pain	Begins with or just before bleeding; usually lasts 8–72 hours	May extend beyond menses; often with non-cyclical pelvic pain
Associated features	Nausea, headache, fatigue; otherwise well	Deep dyspareunia, menorrhagia, IMB/PCB, cyclical bowel/bladder symptoms, subfertility
Examination	Normal	May be normal, or pelvic signs (mass, fixed/enlarged uterus, fornix nodularity, adnexal tenderness)

🧠 Clinical pearl Cyclical bowel or bladder symptoms are the tell. Period-related painful bowel motions, or cyclical haematuria or dysuria, are easily mislabelled for years as IBS or recurrent UTI before endometriosis is considered. It is the cyclicity – symptoms tracking the period – that should send you down the gynaecology pathway rather than the gastroenterology or urology one.

Source: NICE NG73

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