Loneliness as a Risk Factor for Cardiovascular Disease: A Narrative Review

Cardiovascular diseases (CVDs) remain the leading cause of death worldwide, and growing evidence identifies loneliness as an independent psychosocial risk factor for cardiovascular health. This narrative review summarizes current evidence on the biological and behavioral mechanisms linking loneliness with CVD, based on peer-reviewed studies published between 2021 and 2026 retrieved from PubMed, Google Scholar, and Scopus. The literature indicates that loneliness acts as a chronic stressor, promoting activation of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system, which contributes to systemic inflammation, impaired heart rate variability, and increased allostatic load. In addition, it encourages unhealthy behaviors such as smoking, poor diet, physical inactivity, and social withdrawal, further increasing cardiovascular risk. Overall, the evidence suggests that loneliness contributes to both the development and progression of CVD through interconnected biological and behavioral pathways. As a modifiable risk factor, loneliness should be identified early in clinical practice, and addressed through interventions such as social prescribing, cognitive behavioral approaches, and community-based programs.