Comorbidity: What is it and why is it important?

Abstract

Comorbidity refers to any distinct clinical entity that coexists with or occurs during the clinical course of another illness or condition. In other words, it refers to the co-occurrence of two or more distinct illnesses, disorders or conditions in a single individual. As a result of the comorbidity, some disorders tend to occur together more often than they occur alone. For example, anxiety, depressed mood and impaired sleep often co-occur, and in this instance, the co-occurrence appears to be the rule rather than the exception.