[The Silent Risk: Loneliness and Health]

Loneliness has gained significant scientific and public health relevance. Prevalence follows a U-shaped pattern across the life course, with especially high rates in vulnerable groups. Its emergence reflects an interplay of individual, relational, community and structural factors. Longitudinal evidence links loneliness consistently to depression, anxiety, suicidality, cardiometabolic disease, cognitive decline and mortality. Targeted interventions can reduce loneliness, though the growing use of generative AI as emotional support introduces ethical and psychosocial concerns. Overall, loneliness is a key socially rooted risk factor that requires integrated, multi-level strategies for effective prevention and reduction.