BackgroundThere is extensive available research on the relationship between fear of COVID-19 pandemic and physical symptoms. This study was the first to examine the cyberchondria and COVID-19 preventive behavior as mediators of this relationship.MethodsA cross-sectional study was conducted from October to December 2021, during the fourth wave of the COVID-19 pandemic in Russia. The participants were 2,011 Russian-speaking volunteers aged 18 years and older. They completed questionnaires on somatic burden, cyberchondria, COVID-19 preventive behavior, and fear of COVID-19 pandemic. Mediation analysis was used to explore the mediating roles of cyberchondria and preventive behavior in the relationship between fear of COVID-19 and somatic burden.ResultsFear of COVID-19 positively predicted somatic burden, cyberchondria, and COVID-19 preventive behavior. Mediation analysis showed that the relationship between fear of COVID-19 pandemic and somatic burden was mediated by cyberchondria (effect = 0.08, bootstrapping SE = 0.01, bootstrapping 95% CI [0.08, 0.12]), but not COVID-19 preventive behavior (effect = 0.02, bootstrapping SE = 0.01, bootstrapping 95% CI [0.00, 0.05]).ConclusionThe findings suggest that cyberchondria had negative effects on somatic burden during the COVID-19 pandemic. The knowledge of the mediating role of cyberchondria may be used by health care workers when consulting persons with physical health complaints and psychosomatic disorders.