Giavonni Morgagni founded pathological anatomy, the study of the structure and appearance of diseased or abnormal tissues. He laid the foundations for the pathological anatomical investigations of Leopold Auenbrugger (1722-1809), Matthew Baillie (1761-1823), Xavier Bichat (1771-1802), René-Théophile-Hyacinthe Laënnec (1781-1826), Jean Cruveilhier (1791-1874), and Rudolf Virchow (1821-1902), all of whom frankly acknowledged his influence.

Born in Forli, Italy, Morgagni attended schools there until entering the University of Bologna in 1698. The student and protégeacute; of Antonio Valsalva (1666-1723), he was elected to the Accademia degli Inquieti, a distinguished scholarly society, in 1699. He received in Bologna degrees in philosophy and medicine in 1701, became head of the Accademia in 1704, and practiced medicine and studied anatomy in three hospitals in Bologna until 1707, when he moved to Venice. Back in Forli in 1709, he practiced medicine until he accepted an invitation in 1711 to teach at the University of Padua. He taught medicine until 1716 and anatomy until his death, also in Padua.

Morgagni's masterpiece, De sedibus et causis morborum per anatomen indagatis libri quinque (The Seats and Causes of Diseases Investigated by Anatomy in Five Books) (1761), is a classic of pathology. Culminating a lifetime of meticulous study, it was the first medical treatise to correlate accurately a large variety of pathological findings in living patients with their anatomical conditions post mortem. Its seventy chapters contain accounts of 700 cases. Among its findings are the first reliable descriptions of mitral stenosis, angina pectoris, various syphilitic manifestations, several kinds of aneurysm, atrophy of the liver, tuberculosis of the kidney, the eye disease called Morgagni's cataract, and the heart disease called Morgagni-Adams-Stokes syndrome.

Before De sedibus, Morgagni wrote a series of short anatomical tracts called Adversaria anatomica. In them he furthered Valsalva's work and that of Valsalva's teacher, Marcello Malpighi (1628-1694), especially as regards the circulatory system. Also in the Adversaria Anatomica Morgagni reported many of his minor anatomical discoveries, including structures in the trachea, urethra, and genitalia. About twenty-five anatomical structures are named after him. His early studies of normal anatomy prepared him well to recognize the pathological deviations from healthy tissue that he later reported in De sedibus.