Healthy Benefits of Laughter:
Hormones: Laughter reduces the level of stress hormones like cortisol, epinephrine, adrenaline, dopamine and growth hormone.
It also increases the level of health-enhancing hormones like endorphins, and neurotransmitters. Laughter increases the number of antibody-producing cells and enhances the effectiveness of T cells. All this means a stronger immune system, as well as fewer physical effects of stress.
Physical Release: Have you ever felt like you "have to laugh or I'll cry"? Have you experienced the cleansed feeling after a good laugh? Laughter provides a physical and emotional release.
Internal Workout: A good belly laugh exercises the diaphragm, contracts the abs and even works out the shoulders, leaving muscles more relaxed afterward. It even provides a good workout for the heart.
Distraction: Laughter brings the focus away from anger, guilt, (shame) stress and negative emotions, in a than other mere distractions.
Perspective: Sudies show that our response to stressful events can be altered by whether we view something as a 'threat' or a 'challenge'. Humor can give us a more lighthearted perspective and help us view events as 'challenges', thereby making them less threatening and more positive.
Social Benefits of Laughter: Laughter connects us with others. Also, laughter is contagious, so if you bring more laughter into your life, you can most likely help others around you to laugh more, and realize these benefits as well. By elevating the mood of those around you, you can reduce their stress levels, and perhaps improve the quality of social interaction you experience with them, reducing your stress level even more!
How To Use Laughter :
A recent study showed that pre-school-aged children laugh up to 400 times a day, but by the time we reach adulthood, we laugh a mere 17 times per day on average! You can raise your laughter level with the following strategies:
T.V. and Movies: There's no shortage of comedies out there, both at the theater and in the aisles of the video stores, as well as right on your T.V. While wasting your time watching something marginally funny may actually frustrate you, watching truly hilarious movies and shows is an easy way to get laughter into your life whenever you need it.
Laugh With Friends: Going to a movie or comedy club with friends is a great way to get more laughter in your life. The contagious effects of laughter may mean you'll laugh more than you otherwise would have during the show, plus you'll have jokes to reference at later times. Having friends over for a party or game night is also a great setup for laughter and other good feelings.
Find Humor In Your Life: Instead of complaining about life's frustrations, try to laugh about them. If something is so frustrating or depressing it's ridiculous, realize that you could 'look back on it and laugh.' Think of how it will sound as a story you could tell to your friends, and then see if you can laugh about it now. With this attitude, you may also find yourself being more lighthearted and silly, giving yourself and those around you more to laugh about. Approach life in a more mirthful way and you'll find you're less stressed about negative events, and you'll achieve the health benefits of laughter.
'Fake It Until You Make It': Just as studies show the positive effects of smiling occur whether the smile is fake or real, faked laughter also provides the benefits mentioned above. So smile more, and fake laughter; you'll still achieve positive effects, and the fake merriment may lead to real smiles and laughter.
Over 10,000 doctors, nurses, psychologists and other health professionals have attended a training event involving The Happiness Project over the last six years. Modern medicine, so often accused of being over-chemical, over-technical, over-reductionist and over-preoccupied with illness, is showing
a renewed willingness to explore the potential medicinal role of laughter, happiness, love, touch, music, play, tears and smiling, for instance, in health. Intuitively, we know that laughter is good for us. Think for a moment how your body feels whenever you laugh or smile - words like "relaxed", "warm", "whole", "free" and "light hearted" often come to mind. Trust your inner-tuition! Laughter, happiness and a joyful heart really do offer a medicinal, therapeutic touch. It is as if health, happiness, humour and a sense of wholeness are a wonderful string quartet that plays a healing harmony and a marvellous melody. Laughter is the best medicine.
Personally, it has worked for me in my life.
Pop it a Comdey DVD and have a good laugh 
However, I don't like to laugh at the expense of others. Sarcasm and cruelty, in the guise of being humorous, or fobbed off as such, seems like being nasty, to me.
Love, Leah ~ who laughs at herself, frequently.