Our social relations influence our health not only psychologically but also biologically. For the elderly being socially isolated is as bad for their health as having diabetes or high blood pressure. For teenagers it is as bad as being obese or physically inactive. In youth and old age there is a direct relationship between number of friends and health. Health is often measured taking into consideration five variables associated with mortality: systolic and diastolic blood pressure, glycemia, blood cholesterol, girth and inflammation (ESD and CPR assay). Some people have few friends because they are shy or don’t have time, or live in isolated places or couldn’t be bothered. You can’t teach people to be friendly, but teachers, trainers, social assistants, architects, doctors and all those people who deal with people can do a lot to create the conditions that favor social relations.