According to Dr. Martin Samuels, professor of neurology at Harvard Medical School, blacking out while laughing may be related to over-breathing, and is probably not too dangerous.
“This is most likely benign and unlikely that it would lead to death,” he says.
But that doesn’t mean death doesn’t sometimes wear a smile. In the third century B.C., the Greek philosopher Chrysippus was said to have died laughing after getting his donkey drunk on wine. More recently, a Danish audiologist died laughing in 1989 while watching “A Fish Called Wanda.” (It’s also the subject of an old Monty Python sketch, in which a writer pens the “funniest joke in the world” — and immediately dies.)
“Happy news is just as dangerous as sad news with regard to the risk of sudden death,” he says.