Social withdrawal has recently been recognized by the Istituto Superiore di Sanità (the Italian National Institute of Health) as one of the most common problems among adolescents in the post pandemic world, with an onset estimated between 11 and 13 years of age. Both the paediatrician’s office and the school are a primary observation point for the early identification of the problem. This article describes the possible manifestations of social withdrawal in adolescence, underlying risk factors and comorbidities (i.e. psychological vulnerability, difficulties in the relationship within and outside the family, internet addiction, anxious somatizations and neurodivergent condition), focusing on the role that the paediatrician can play in the early detection of risk factors and on the importance of a careful and informed approach to youth at risk. For the paediatrician, it is essential to establish a collaborative relationship with the parents and to be aware of the resources locally available to address the problem.