In a sense, Renaissance medicine could be described as beginning with the rediscovery of ancient medicine and ending with the repudiation of ancient medicine.
During the middle ages, knowledge of much of ancient Greek and Latin medicine was lost in the Latin west. The Renaissance or "rebirth" of knowledge was a recovery of antiquity due to two major factors, contact with Arabic culture in Moorish Spain and the fall of Constantinople resulting in many Greeks being exiled to Italy.
The first wave of transmission of ancient medical culture to the Latin west actually started in the twelfth and thirteenth centuries in Toledo, Spain, where Muslims, Jews, and Christians lived in relative harmony, and many works of Aristotle were first translated into Latin. The two most important texts of ancient medicine were the Hippocratic Corpus and the works of Galen, which both were very influential in the late middle ages and early Renaissance.
The first western medical school, Schola Medica Salernitana (in Salerno, Italy), was established in the twelfth century, and was a center for dissemination of Greek and Arabic medical knowledge; it continued to be an important medical center in the Renaissance.
The main innovation of the Renaissance was that after a prolonged period of recovery of ancient knowledge, slowly empirical studies began to replace received wisdom. Increasingly accurate anatomy texts, based on dissection of cadavers, were written by Andreas Vesalius (1514-64), Gabriele Falloppio (1523-62), and Girolamo Fabrizio. William Harvey, in 1628, discovered that the heart acts as a pump to circulate blood.
Although Renaissance doctors did not understand the origin of infectious diseases, and periodic outbreaks of epidemics such as plague and smallpox caused huge death tolls in crowded and unsanitary cities, both pharmacology and surgery became increasingly sophisticated in this period. Infant mortality rates were close to 30 percent, and childbirth, attended by midwives, also had a high mortality rate.