Summary of findings related to therapeutic benefits of laughter:

  1. Activates and strenghtens the immune system
  2. Reduces at least four hormones associated with stress
  3. Provides aerobic workout and increases body's ability to use oxygen
  4. Relaxes the muscles
  5. Can significantly reduce pain for long periods of time
  6. Lowers blood pressure and can prevent hypertension
  7. Improves respiration by emptying lungs of air they take in
  8. Has no negative side effects for most people
  9. Is free and available anywhere without a prescription 

(Urban, Hal. Positive Words, Powerful Result. p 105-115. NY: Fireside Book, 2004).