It seems in movies that almost invariably when people have a trickle of blood in the corner of their mouth they are dead or dying. Is this just a Hollywood thing? Or do fatal injuries (to the head or gut or elsewhere) have a propensity to cause people to bleed from the mouth in real life?
Any significant trauma to the head can easily cause bleeding from the mouth, usually from the lips or gums being lacerated. Crushing blows or gunshot wounds to the chest or abdomen which would cause hemorrhage into the lungs or esophagus can result in blood coming from the mouth too. If you’re dying of congestive heart failure, your lungs fill with fluid, and it’ll be at least a bit bloody. Ditto for death from pneumonia. But in general, nothing about death itself necessitates that one cough up blood. It’s the mechanism of demise which determines if this is to be.
I’m sure a good bit of it is Hollywood. I’ve even speculated that it’s an easy-to-identify symbol: trickle of blood from the mouth = serious or fatal injury, but still enough for the affected character to spout off a last few lines.
I know that one could cough up blood, as a result of bleeding into the lungs. An injured preson could also bite their own tonuge and get the blood that way, but those darn tongue injuries sure screw up one’s diction.