Aneurysmal subarachnoid hemorrhage (SAH) is a neurological emergency with high 
risk of neurological decline and death. Although the presentation of a 
thunderclap headache or the worst headache of a patient's life easily triggers 
the evaluation for SAH, subtle presentations are still missed. The gold standard 
for diagnostic evaluation of SAH remains noncontrast head computed tomography 
(CT) followed by lumbar puncture if the CT is negative for SAH. Management of 
patients with SAH follows standard resuscitation of critically ill patients with 
the emphasis on reducing risks of rebleeding and avoiding secondary brain 
injuries.