somebody like this comes to the hospital. typically the goal is to basically decompress the brain so the brain doesn't have this pressure, remove the blood collection. if someone doesn't show up at the hospital within hours you could accumulate enough blood in sadly have this outcome. . >> they don't know until it's really too late. you know, the bump on the head may not seem like a big deal. how common is this, sanjay? >> well, you know, people who have blows to the head and then develop some bleeding on the brain, that's not usual. the idea that someone would die of it and not having it checked out or anything, that is unusual. there are certain risk factors. people who are older. as you get older, your brain starts to shrink a bit. as a result, you have more room to accommodate some of that blood. so that could be an issue. someone on blood thinners could take what would have been an innocuous amount of bleeding and turned it into something