In article we showed new approaches to consideration of social practices on example of healthcare behavior. On the basis of modern interpretation of theory of understanding sociology (by M. Veber) and phenomenological sociology (by A. Shutz) we showed the healthcare behavior as a special form of purposeful and rational activity in casual practices of modern youths. We revealed main determinants, which contribute to healthy lifestyle of youths. There are four groups of factors: environment, satisfaction of needs, lifestyle and social institutes.