Lead author Dr. Monique H.M. Vlak, a neurologist at the University Medical Center in Utrecht, Netherlands, said an intracranial aneurysm is a weakness in the wall of a brain blood vessel that often causes it to balloon. If it ruptures, it can result in a subarachnoid hemorrhage which is a stroke caused by bleeding at the base of the brain.
An estimated 2 percent of the general population have intracranial aneurysms, but few rupture, Vlak explained.
Vlak and colleagues identified eight factors and their contribution to the risk of a subarachnoid hemorrhages:
-- Coffee consumption at 10.6 percent.
-- Vigorous physical exercise at 7.9 percent.
-- Nose blowing at 5.4 percent.
-- Sexual intercourse at 4.3 percent.
-- Straining to defecate at 3.6 percent.
-- Cola consumption at 3.5 percent.
-- Being startled at 2.7 percent.
-- Being angry at 1.3 percent.
"All of the triggers induce a sudden and short increase in blood pressure, which seems a possible common cause for aneurysmal rupture," Vlak said in a statement.
The study was published in Stroke: Journal of the American Heart Association.