while being under heavy pressure from the surroundings. So living organisms are not understood based on componds alone, and we must look at their more or less vulnerable organs and life processes. In the same way we need to re-define our concept of health, from absence of single diseases towards the ability of the organism to maintain a complex balance in the organs and the life processes during the major changes taking place recurringly during our life cycle. The book presents in a popular way a spectrum of vitality examples, taken from research and everyday life.