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Emergency MedicineNeurology

Suspected Subarachnoid Haemorrhage

Thunderclap headache assessment — Ottawa SAH rule, CT within 6h, LP after 12h if CT negative, neurosurgical referral.

Source: NICE NG228; RCEM 2023; AHA/ASA 2023

Step 1 of ~9
info

Red-Flag Headache Assessment

Sudden severe (thunderclap) headache reaching peak intensity within 1 minute, often described as 'worst ever'. Other red flags: neck stiffness, photophobia, focal neurology, altered consciousness, seizure, syncope at onset, age >50 first severe headache, exertional onset.

Related

Curated clinical cross-links plus same-class fallbacks.

Decision support only. Always apply local guidelines and clinical judgement.