Brain fog is a physiological condition caused by stress, mental strain, lack of sleep, or too much mental work for a long time. This situation can have many negative effects on a person's performance and mood and may cause a decrease in concentration, memory loss and depression. Therefore, according to what was said, the present study was conducted with the aim of providing a model of the antecedents and consequences of brain fog among hospital crews and employees. This research is a fundamental research which is philosophically interpretative and has an exploratory approach in terms of nature. Considering that there is no previous theory about brain fog among hospital employees and crews, therefore, in order to solve the problem of research and formulation of the brain fog model among the employees and crews of the hospitals, the qualitative research method was used, and specifically, the data-based theory method was used to construct the theory. In the current research, the statistical population was the hospital staff and 16 of them were selected as a sample by theoretical sampling. In this research, the criterion of reaching 16 experts, which is the saturation point, is the point where the connection between the concepts and the new class no longer appears. The results showed that individual factors, family factors, motivational factors and occupational factors are among the antecedents of brain fog and individual and organizational consequences are among the consequences of brain fog.