A study has found that drinking coffee, have sex, or even blowing your nose, could temporarily raise your risk of rupturing a brain aneurysm and suffering a stroke.
Dutch researchers identified eight main triggers that appear to increase the risk of intracranial aneurysm (IA), 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 per cent of the general population have IAs, but few rupture.
Calculating population attributable risk, the fraction of subarachnoid haemorrhages that can be attributed to a particular trigger factor, the researchers identified the eight factors and their contribution to the risk.
It was found that coffee consumption contributed 10.6 per cent, vigorous physical exercise 7.9 per cent, nose blowing 5.4 per cent, sexual intercourse 4.3 per cent, straining to defecate 3.6 per cent, cola consumption 3.5 per cent, being startled 2.7 per cent, and being angry 1.3 per cent.
"All of the triggers induce a sudden and short increase in blood pressure, which seems a possible common cause for aneurysmal rupture," Monique H.M. Vlak, M.D., lead author of the study and a neurologist at the University Medical Center in Utrecht, the Netherlands, said.
Risk was higher shortly after drinking alcohol, but decreased quickly, researchers said.
"Subarachnoid haemorrhage caused by the rupture of an intracranial aneurysm is a devastating event that often affects young adults.
"These trigger factors we found are superimposed on known risk factors, including female gender, age and hypertension," Vlak said.
Although physical activity had triggering potential, researchers don't advise refraining from it because it's also an important factor in lowering risk of other cardiovascular diseases.
"Reducing caffeine consumption or treating constipated patients with unruptured IAs with laxatives may lower the risk of subarachnoid haemorrhage," Vlak said.
"Whether prescribing antihypertensive drugs to patients with unruptured IAs is beneficial in terms of preventing aneurysmal rupture still needs to be further investigated," Vlak added.
The study has been published in 'Stroke: Journal of the American Heart Association' .