VisualDx is Clinical decision support system (CDSS) software intended to be used by medical practitioners, including primary care practitioners, to assist them in differential diagnosis. In one of its modes of operation, after a healthcare provider enters some basic facts about the patient, VisualDx presents peer-reviewed photographs or diagrams of medical conditions such as skin conditions, ordered from the most to the least likely, to assist in diagnosis. The system holds over 100,000 images.