Appliance of Science: Why do we sometimes cry with laughter?

Laughing and crying are usually associated with two very different emotions and yet we have all cried with laughter at some stage or other, why is that?

Laughing is good for you both mentally and physically.

A few theories

When it comes to evaluating why we sometimes cry while we laugh, science is still playing catch up as, the truth is, no one is fully sure why we do it. That doesn’t mean there are not a few scientific theories though, and here are some of them.