According to Madan Kataria, a physician who practices in Bombay, author of Laugh for No Reason (Madhuri International), and founder and president of Laughter Clubs International, laughter may indeed be the best of all medicines. Kataria has developed a form of laughter therapy called Hasya Yoga (hasya means "laughter" in Sanskrit) that combines deep, controlled breathing and stretches with various types of forced laughter.
Kataria likens the use of abdominal muscles during the practice of forced laughter to yoga exercises that tone the digestive system, emphasizing that strong abdominal muscles contribute to a healthy digestive system. He further maintains that laughter practice raises both pulse rate and blood pressure, stimulating and toning the circulatory system, and it strengthens the respiratory system by using the entire capacity of the lungs. Prana—or life force—gains entry to our bodies via breathing, he says, so clear respiratory passages and strong lungs are essential to the well-being of both body and spirit.