How do pathological and etiological classifications of disease differ?

In the study of disease, classifications serve distinct purposes by organizing medical knowledge based on different criteria. While a single condition may be categorized in multiple ways, pathological and etiological classifications differ fundamentally in their focus:1

• Pathological Classification: This approach categorizes diseases based on the nature of the disease process itself. It focuses on the underlying biological mechanisms or structural changes occurring within the body, such as whether a condition is inflammatory or neoplastic (e.g., tumors and cancers).1
• Etiological Classification: This approach is based on the cause or origin of the disease, provided that cause is known. It is particularly useful for identifying the specific agents responsible for a condition, such as biotic factors like bacteria (e.g., staphylococcal or rickettsial infections) or other external triggers.12

In summary, while the pathological classification describes how a disease manifests and progresses within the body, the etiological classification identifies why the disease occurred by pinpointing its specific cause.1