Binge drinking in particular may increase the risk. Cigarette smoking, high blood pressure, and excessive alcohol use are also risk factors for stroke. Most people never realize they have a cerebral aneurysm until it ruptures and causes a subarachnoid hemorrhage. The bleeding from the aneurysm is usually not directly into the brain, but into the subarachnoid space around the brain. The headache may be accompanied by nausea and vomiting.
Some patients lose consciousness or faint briefly.
Up to one half of patients with a subarachnoid hemorrhage have had a similar but usually not as severe headache in the days or weeks prior to the headache for which they seek medical attention. This is thought to be due to a minor bleeding episode or small leak from the aneurysm before the large hemorrhage occurs. In addition to a severe headache, a ruptured aneurysm often causes a stiff neck, sleepiness, and may result in difficulty seeing, double vision or weakness in the arms or legs. The symptoms vary depending on the size and location of the hemorrhage. A subarachnoid hemorrhage from a ruptured aneurysm is life-threatening.