Coffee, sex and blowing your nose could increase the risk of a type of stroke, say researchers in the Netherlands.
The study on 250 patients identified eight risk factors linked to bleeding on the brain.
They all increase blood pressure which could result in blood vessels bursting, according to research published in the journal Stroke.
The Stroke Association said more research was needed to see if the triggers caused the rupture.
More than 150,000 people in the UK have a stroke each year with nearly 29,000 due to bleeding on the brain.
Bleeding can happen when a weakened blood vessel, known as a brain aneurysm, bursts. This can result in brain damage or death.
The researchers at the University Medical Center in Utrecht looked at 250 patients for three years to identify what triggers ruptures.
They found that coffee was responsible for more than one in 10 burst brain aneurysms.
While people drinking coffee had only a 1.7 times greater risk, it is more common than other risk factors.
Being startled increased the risk by more than 23 times, but was responsible for just 2.7% of cases.
Dr Monique Vlak, a neurologist and the study's lead author, said: "All of the triggers induce a sudden and short increase in blood pressure, which seems a possible common cause for aneurysmal rupture."
