Can sex increase risk of cerebral aneurysm rupture? Although the risk is extremely small, research suggests that people who have aneurysms should be careful.

Aneurysms occur when the wall of an artery weakens and bulges out. They can occur anywhere in the body, but are particularly dangerous in the brain, where they can cause a hemorrhagic (bleeding) stroke if they burst.

In a study published earlier this year in the journal Stroke, researchers asked 250 patients who had suffered a ruptured brain aneurysm about their exposure to 30 possible triggers before the hemorrhage.

The investigators found that being startled raised the risk of suffering from a ruptured aneurysm by the highest level — 23-fold. Anger also boosted the risk by six times. Other things raised the level included:

• Drinking coffee, blowing your nose, vigorous physical activity (twice as likely to suffer a ruptured aneurysm)
• Drinking cola (three times)
• Straining for defecation (seven times)
• Sexual intercourse (11 times)

According to Dr. Ciaran Powers, assistant professor of medicine at Ohio State University, doctors treating aneurysms note that patients often report a splitting headache — the most common sign of a rupture — right after sex or while straining to to make a bowel movement.