Comorbidity

In medicine, comorbidity refers to the simultaneous presence of two or more medical conditions in a person; often co-occurring (that is, concomitant or concurrent) with a primary condition. It originates from the Latin term morbus (meaning "sickness") prefixed with co- ("together") and suffixed with -ity (to indicate a state or condition). Comorbidity includes all additional ailments a person may experience alongside a primary diagnosis, which can be either physiological or psychological in nature. In the context of mental health, comorbidity may refer to the concurrent existence of mental disorders, for example, the co-occurrence of depressive and anxiety disorders. The concept of multimorbidity is related to comorbidity but is different in its definition and approach, focusing on the presence of multiple diseases or conditions in a person without the need to specify one as primary.

Definition

The term "comorbid" has three definitions:

to indicate a medical condition existing simultaneously but independently with another condition in a patient.

to indicate a medical condition in a patient that causes, is caused by, or is otherwise related to another condition in the same patient.

to indicate two or more medical conditions existing simultaneously regardless of their causal relationship.

Comorbidity can indicate either a condition existing simultaneously, but independently with another condition or a related derivative medical condition. The latter sense of the term causes some overlap with the concept of complications.