Diagnosis
Diagnosis, in medicine, the determination of the nature of a disease. Modern diagnosis combines the taking of the patient's health history, a physical examination, and laboratory and radiological examinations. Some diseases, such as measles and mumps, are fairly easy to identify by appearance. Other problems, such as broken bones, are often suspected on the basis of symptoms and confirmed by X-ray observation. With many symptoms, however, more complex testing is needed. Establishing the presence of a gastric ulcer, for example, is helped by inserting a tube called an endoscope into the stomach. Coronary artery disease may be suspected due to the presence of chest pains and an abnormal electrocardiogram (see Electrocardiography ); definitive evidence, however, comes only from an angiogram, in which dye is injected into the coronary arteries (see Heart Diseases ). A diagnosis of cancer often requires a biopsy, or microscopic examination of tissues. Diagnosis of disease in a fetus i