Giggle, snort, and laugh till it hurts. You -- and everyone around you -- will be healthier.

In a recent study, sounds of laughter or cheering triggered strong brain activity in listeners, particularly the brain areas that control the muscles of the face -- which means listeners were primed to smile or laugh, too. The response was automatic -- and contagious.

Laughter is good for both body and soul. It can thwart stress, boost the immune system, and help protect against the flu and even cancer. In a study, men who watched a favorite funny video had lower levels of stress hormones and higher amounts of growth hormone, both of which bolster the immune response. And study participants had more of the natural killer cells that target tumors and viruses.

Just anticipating a chuckle or guffaw can keep you healthy and reduce stress. In another study, people who knew in advance that they would be watching a funny movie had elevated levels of growth hormone and more beta-endorphins (feel-good brain chemicals that block pain and help you relax). And these levels held steady throughout the hour of viewing as well as afterwards, for up to 24 hours. A mere 30 minutes of comic relief may be all you need for similar health benefits.

So go ahead, laugh often and out loud. It's your -- and your friends', family's, and cronies' -- best medicine.

Happier is healthier -- but if your mind isn't there yet, read this article on get-happy strategies.

Just not much of a giggler? Here are other stress reduction strategies.