RESUMO
@#Headaches are a common presentation in the emergency department (ED). Even though not all are potentially serious, some such as subarachnoid hemorrhage (SAH) can be more dangerous than others. SAH is a medical emergency with an almost 50% mortality rate. It is crucial not to miss the diagnosis of SAH, as a missed or delayed diagnosis can be severely detrimental. It classically presents as thunderclap headache, a severe, sudden-onset headache. There are various approaches in diagnosing or excluding SAH, which is classically done by performing a computed tomography (CT) scan followed by a lumbar puncture (LP). But with the improved sensitivity of more modern diagnostic tools, more physicians are in support of changing this classical teaching. The aim of this case report is to review the advantages and disadvantages of LP in diagnosing SAH, along with other diagnostic tools commonly used.