Mental illness is increasing among high school girls. At the same time the use of social media is increasing which is considered to be a major part of Western society. Increased body weight is considered to be associated with dissatisfaction whit the appearance. A dissatisfaction whit body perception can lead to problems such as depression, anorexia nervosa, self-injury and drug abuse. Never before has it been considered as difficult as it is today to fit into the today's society regarding apperance and it has been a negative trend over recent years. Through increased self-confidence and physical activity can body perception be improved. The purpose of the study was to investigate the thoughts of high school girls regarding how body perception, body ideals and living habits affect their health. Through semistructured interviews of six high school girls the study's empirical content was obtained from which further a inductive qualitative concentanylsis was conducted. The results of the study showed that the thoughts differ and aspects which affect the health most are considered to be the circle of friends and social media. Furthermore, the result showed that the individuals need to find factors in life to create and maintain good health, these factors differ from each individual. In addition to this, the result showed that physical activity, in excessive amounts, did contribute to a better health. From a public-health perspective is it important to increase the health of the population and prevent mental illness, especially among the young people who are the future of Sweden. Further studies on the subject can lead to more and better methods and strategies to prevent mental illness among high school girls.