Have you had a headache this week? If you have children then the answer is inevitably, "yes". Many paediatric patients present with headache that frequently gets better with simple analgesia and some fluid. But how about the patient with "the worst headache ever"? Could this be something far more serious? Sometime paediatric trainee and part-time holidaymaker Dr Charlotte Mowbray-Pratt summarises the approach to the child who just might have had a subarachnoid haemorrhage.