Summary

• Presents as a sudden severe headache, often described as 'the worst headache of life', with nausea, vomiting, and photophobia.
• Examination can be normal or may reveal altered consciousness, meningismus, intraocular haemorrhages, or focal findings.
• CT indicated if subarachnoid haemorrhage is clinically suspected. Lumbar puncture (LP) is indicated if CT is unrevealing. Cerebral angiography confirms the presence of aneurysms.
• Initial stabilisation followed by surgical clipping or endovascular coil embolisation is standard therapy.
• Complications are common and include rebleeding, acute hydrocephalus, and vasospasm.