What is the main factor in classifying a disease as 'pathogenic'?

The classification of a disease as pathogenic is primarily based on its origin from living organisms, which includes bacteria, viruses, fungi, or parasites. These living agents can enter the body and disrupt normal physiological functions, leading to illness or disease. This defining characteristic of being produced by living organisms differentiates pathogenic diseases from conditions that may arise from non-living causes such as environmental factors or physical injuries.

While hereditary conditions can lead to disease, they do not fall under the category of pathogenic diseases because they do not result from infectious agents. Similarly, diseases caused by physical injuries might not involve any living organism and hence are termed trauma or injury-related instead of pathogenic. The notion that pathogenic diseases must always be fatal is also misleading; many are treatable and not necessarily life-threatening, further reinforcing that the essence of pathogenic classification lies in the involvement of living organisms.