
Human blood contains receptors which receive signal of happiness from the brain and pass them. Then the process of healing is made faster. Hence, the more you laugh, the healthier you become, and the healthier you become the more your personality rejuvenates.
By smiling, laughing and wearing cheerful expressions, we strengthen the immune system to prevent and fight diseases.
If tension, stress and anxiety make a man sick, then its sure happiness, cheerfulness, contentment and joy should help a man cure his diseases. As for old age, "It is a state...