Diagnosis

Diagnosis, the art of distinguishing between different forms of disease. Diagnosis is based upon an analysis of symptoms (phenomena observed by the patient) and physical signs (phenomena observed by the physician). The methods employed in the detection and elucidation of physical signs have been greatly perfected within recent years. The methods of percussion of the chest, invented by Avenbrugger, and of auscultation, invented by Laennec, threw much light upon thoracic affections. Methodical examination of the urine has proved of the greatest service in detecting many forms of disease. Again, the laryngoscope and the ophthalmoscope, and the employment of electricity, have greatly perfected the means available for arriving at a correct diagnosis. The latest development of the art of diagnosis consists in the application of bacteriological investigation, as, for example, to the sputum of cases of suspected phthisis.