Laughter triggers the release of endorphins, those chemicals in the brain that induce feelings of euphoria.  A good giggle can also suppress the production of cortisol, a hormone released when you’re under stress and one that can influence blood pressure, causing your body to retain salt.  Laughter is nonfattening.  It’s also contagious, and engaging in it frequently will contribute to a nicer world.

Source:  “Be Happy, Be Healthy,” United Health Foundation, www.unitedhealthfoundation.org.