Pathology << puh THOL uh jee >> is the study of disease, or any condition that limits the power, length, or enjoyment of life. Comparative pathology compares human diseases with those of animals. Human pathology is a branch of medicine. Pathologists use modern instruments and methods, such as electron microscopy, to recognize the changes caused by disease in the tissues and organs of the body. They try to explain why a diseased body acts differently from a healthy body.
Pathologists use their knowledge of diseased tissues and body fluids to aid the physician. Pathological tests help physicians diagnose a disease and the extent of its attack. These tests may include examination of the blood, urine, and tissues. The use of laboratory tests to diagnose disease is called clinical pathology.
Pathologists also study diseased parts removed by surgery. They may examine corpses to learn the exact cause of death. This examination is called an autopsy, or post-mortem examination.
Special kinds of pathology study diseases of separate organ systems. For example, neuropathology concerns diseases of the nerves.
See also Forensic pathology; Gnotobiotics; Virchow, Rudolf; Morgagni, Giovanni B.