Yet researchers aren't sure if it's actually the act of laughing that makes people feel better. A good sense of humor, a positive attitude, and the support of friends and family might play a role, too.
"The definitive research into the potential health benefits of laughter just hasn't been done yet," says Robert R. Provine, professor of psychology and neuroscience at the University of Maryland, Baltimore County and author of Laughter: A Scientific Investigation.
But while we don't know for sure that laughter helps people feel better, it certainly isn't hurting.
Laughter Therapy: What Happens When We Laugh?
We change physiologically when we laugh. We stretch muscles throughout our face and body, our pulse and blood pressure go up, and we breathe faster, sending more oxygen to our tissues.
People who believe in the benefits of laughter say it can be like a mild workout -- and may offer some of the same advantages as a workout.
"The effects of laughter and exercise are very similar," says Wilson. "Combining laughter and movement, like waving your arms, is a great way to boost your heart rate."
One pioneer in laughter research, William Fry, claimed it took ten minutes on a rowing machine for his heart rate to reach the level it would after just one minute of hearty laughter.
And laughter appears to burn calories, too. Maciej Buchowski, a researcher from Vanderbilt University, conducted a small study in which he measured the amount of calories expended in laughing. It turned out that 10-15 minutes of laughter burned 50 calories.
While the results are intriguing, don't be too hasty in ditching that treadmill. One piece of chocolate has about 50 calories; at the rate of 50 calories per hour, losing one pound would require about 12 hours of concentrated laughter!