Narrator: This is Science Today. A link has been found between cigarette smoking and ruptured cerebral aneurysms, which may help doctors decide which patients should undergo early detection for treatment. Dr. Clay Johnston of the University of California, San Francisco says not all aneurysms rupture, but when they do, they're devastating.
Johnston: About fifty percent of people where that's occurred will die from it and then at least half of those that don't die will have some kind f permanent disability from it. Occasionally we'll find these aneurysms before they rupture. So we'll see the dilation in the blood vessel, usually on some kind of imaging study, some kind of scan.
Narrator: Aside from smoking, Johnston says there are several other risk factors for ruptured aneurysms, including age, hypertension and drinking.
Johnston: Family history also, people with family histories tend to be more likely to have one. So there's some predisposition that you're born with, probably and superimposed on that are things you do in your life - your other diseases, like hypertension.
Narrator: For Science Today, I'm Larissa Branin.