Morbus

Morbus is the Latin word for disease or illness. In medical literature, especially in historical texts and German-language usage, the term has been adopted as a formal label in the names of certain diseases.

Historically, morbus was used with eponymous or descriptive elements: Morbus Crohn (Crohn's disease), Morbus Parkinson (Parkinson's disease), Morbus Alzheimer (Alzheimer's disease), Morbus Hansen (Hansen's disease, leprosy), Morbus Paget (Paget's disease). This reflects a Latin tradition in which diseases were named for the condition itself or for the physician or discoverer associated with them.

In modern English medical writing, the term morbus is rarely used outside historical context; "disease" or the eponymous name (Crohn's disease, Parkinson's disease, Alzheimer's disease) is preferred. Some German medical texts nevertheless retain Morbus as part of the official designation for certain conditions.

The use of morbus illustrates the evolution of medical nomenclature, from Latin-based labeling to standardized, internationally used terminology. See also disease, medical Latin, eponym, and list of diseases.