Smoking may exacerbate the increased risk of a blood vessel bursting inside the brain (intracerebral stroke) already faced by people with high blood pressure, according to a new study in Stroke: Journal of the American Heart Association. For every 10 millimeters of mercury (mm Hg) increase in systolic blood pressure (the top number in a reading), smokers face an additional 15 percentage point increase in risk of hemorrhagic stroke (bleeding in the brain), compared with nonsmokers.