Pathognomy refers to the art or science of identifying diseases based on someone's facial expression or body language. Some suitable synonyms for pathognomy are pathodiagnosis, pathognostics, and symptomatology. Pathodiagnosis refers to the diagnosis of a disease based on identifying its symptoms. On the other hand, pathognostics is the study of the nature and diagnosis of diseases based on their symptoms. Lastly, symptomatology is the study and diagnosis of a disease based on its symptoms and signs. These synonyms are helpful for medical professionals and anyone interested in identifying diseases based on the physical and behavioral symptoms exhibited by an individual.