Laughter, like exercise, reduces the heart rate.william fry in 1971 first demonstrated that laughter increases the heart rate,blood pressure, oxygen consumption,and works the muscles in the face and stomach.shortly after, these levels drop, providing a relaxation response. STRESS:- prolonged stress creates unhealty physiological changes.stress causes the adrenal glands to release cortico steroids and high level have an immunosuppressive effect.laughter is an antidote.Berk,Tan,Fry et al reported this in neuroendrocrine and stress homone changes during mirthful laughter American journal of the medical science. 298(6),390-396.scientific evidence has shown that laughter helps people breathe easier and it massages the heart and other vital organs.it also increase the realse of disease-figthing cells in the immune system.like exercise, laughter quicken the pulse and stimulates the cardiovascular system.in experiment, students who watched funny movies were found to have an increased flow of infection-fighting proteins in their saliva.