Table 4.

Comorbidity: key terminology and definitions.

Comorbidity (coincidence and concurrent diseases or comorbid conditions)	This general term refers to the presence of one or more additional diseases or disorders occurring concurrently with a primary disease or disorder. Based on Table 3 categories.
Multimorbidity (polypathology or polymorbidity)	This is the coexistence of two or more chronic diseases or conditions in a patient. The term is often used interchangeably with comorbidity, but while comorbidity refers to the effect of all other diseases an individual patient might have other than the primary disease, multimorbidity refers to the presence of two or more chronic diseases without establishing a primary disease.
Health determinants and indicators	These broader terms encompass a variety of conditions and factors that affect health. For example, in the context of vascular health, this could include both comorbid conditions and risk factors related to vascular diseases.
Comorbid conditions (concurrent disorders and co-existing diseases)	These refer to actual health conditions or diseases an individual has in addition to their primary disease. For instance, in the realm of vascular health, examples could include conditions like heart disease, stroke, and hypertension. These comorbid conditions co-occur with the primary disease and can interact with it in complex ways, potentially impacting treatment and outcomes.
Risk factors (predictors)	These are characteristics or behaviors that increase the likelihood of developing certain diseases. For example, in the case of vascular health, risk factors might include behaviors like smoking, lifestyle factors like lack of exercise or obesity, and genetic predispositions such as family history of vascular disease.