Smoking, Family History Increase Risk of Stroke

Now Woo has done research that looks at the relationship between hemorrhagic strokes and smoking. He says researchers have known smoking is a risk factor for aneurysm formation.

"We also know that having a family member who had a history of aneurysm rupture was also a risk factor for aneurysm formation," Woo says.

Woo looked at several hundred people who had had ruptured aneurysms and compared them to people who did not have aneurysms. He found that people who smoked had double the risk for aneurysm. His analysis also found that those with a family history of aneurysm also had twice the risk of forming one. But people who had the family history and who smoked were six times more likely to have a hemorrhagic stroke. He says that means hundreds of thousands, if not millions of people are at much greater risk of having a hemorrhagic stroke due to a combination of genes and behavior.