Abstract: Objective To explore the etiology of headache after aneurismal subarachnoid hemorrhage (SAH) and find clinical features of various kinds of headache.Methods All of the 107 patients with SAH and intracranial aneurysm diagnosed upon CT scan and angiographic demonstration within 24 hours after onset were evaluated by numeric rating scales (NRS) 1,2,3,5,7,10 and 14 days after SAH. Patients suffered from moderate-severe headache were examined by cranial CT scan and transcranial Doppler (TCD) to find the reason, and their diversities were analyzed.Results 86.9% (93/107) patients with SAH suffered from moderate-severe headache. 9.7% (9/93) of them were caused by rebleeding of untreated aneurysm and the pain always occurred abruptly, always followed by conscious disturbance/new neurological signs. CT scan found hydrocephalus in 16.1% (15/93) patients with headache, they could aggravated with time but sometimes released spontaneously; TCD found intracranial vasospasm in 12.9% (12/93) of patients, their clinical features were no more than other 61.3% (57/93) patients with negative results, but patient's condition could exacerbate caused by later brain ischemia or even infarction.Conclusion Majority of SAH patients suffer from headache.

Key words: aneurismal subarachnoid hemorrhage, complication, etiology