See Talk: Medieval medicine.

There were many scientists and physicians involved in advances in medicine during the Renaissance. The Italian Girolomo Fascastoro was born in 1478. He was the first to propose that epidemic diseases are caused by objects outside the body that could be transmitted by direct or indirect contact or even over long distances without any contact. He also discovered new treatments for diseases such as syphilis. The name for syphilis was derived from his poem written in 1530 which is regarded as the first treatise on the disease. Girolomo died in 1553.

The Flemish Scholar Andreas Vesalius was born in 1514. In 1543 he wrote the first complete textbook on human anatomy: "De Humani Corporis Fabrica" meaning "On the Fabric of the Human Body". Most of Vesalius' work was on human cadavers although much of what he knew came from the translated works of Galen and Hippocrates.

During the 15th and 16th centuries, the works of Hippocrates were rediscovered, translated, and made available to scholars. Ancient knowledge led to advances in Renaissance science. The Greek physician Hippocrates was born 460 B.C and is considered the founder of medicine as a scientific discipline. He wrote about diseases, surgery, and bone fractures as well as human anatomy. He taught at the Hippocratic school in Cos, Greece. He died in 377 B.C Another Greek physician was Galen. Galen was born in 130 A.D He wrote more than 500 treatises on physiology, hygiene, dietetics, pathology, and pharmacology. His most important work in anatomy was his discovery of how the spinal cord controls various muscles. He also identified various nerves, demonstrated that the brain controls the voice, and proved that arteries carry blood, not air. He discovered all this from dissecting live and dead animals. He also described the heart valves and determined the purpose of the bladder and kidneys. Much later, in 1628, William Harvey explained the circulation of blood. He showed that blood flows through the appendages and returns to the heart. It was previously thought that blood was the product of food and was absorbed by muscle tissue.

During the 1500's, Paracelsus began using leeches were used to suck blood and correct imbalances in the human body. Paracelsus was born in 1493. The nickname Paracelsus came from Theoprastus Bombastus for easier pronunciation. His nickname also describes his thought that he was above the roman doctors, like celsus: "para" meaning above. Like Girolomo, he discovered that illness was caused by agents outside the body such as bacteria, not by imbalances within the body.

The infamous Leonardo Da Vinci also had a large impact on medical advances during the Renaissance. Da Vinci was born April 15th, 1452. Along with being a painter, inventor, sculptor, architect, and engineer, Leonardo was a scientist. His approach to science was an observatory one: he tried to understand a phenomenon by describing and depicting it in utmost detail. He did not like to emphasize experiments and theoretical explanations. Throughout his life he planned a large book based on detailed drawings of everything. However, since he lacked education in Latin and Mathematics, he was mostly disregarded by contemporary scholars. He participated in autopsies and created many detailed anatomical drawings, planning a work of comparative human anatomy. His study of the human anatomy led eventually to the design of the first robot. The design was made around 1495 but was only rediscovered in the 1950's. The device was known as Leonardo's Robot. It is still unknown whether there was any attempt to build this device.

The french army doctor Ambroise Pare was born in 1510. Pare resurfaced the Greek way of tying off blood vessels. After amputation the common procedure was to cauterize the open end of the amputated appendage to stop the hemorrhaging. This was done by heating oil, water, or metal and touching it to the wound to seal off the blood vessels. Pare also believed in dressing wounds with clean bandages and ointments, including on he made himself composed of eggs, oil of roses, and turpentine. He was the first to design artificial hands and limbs for amputation patients. On one of the artificial hands, the two pairs of fingers could be moved for simple grabbing and releasing tasks and the hand look perfectly natural underneath a glove.

Medical catastrophes were more common in the Renaissance than they are today. During the Renaissance, trade routes were the perfect transportation for disease. Before the Spanish came to America and Mexico, the deadly germs of smallpox, measles, and influenza were unheard of. The Native Americans did not have the immunities the Europeans developed through long contact with the diseases. Columbus ended the Americas isolation in 1492 while sailing under the flag of Castile, Spain. Deadly epidemics swept across the Caribbean. Smallpox wiped out villages in a matter of months. The city of Hispaniola had a population of 250,000 Native Americans. 20 years later, the population had dramatically dropped to 6,000. 50 years later, it was estimated that approximately 500 Native Americans were left. Smallpox then spread to Mexico where it then helped destroy the Aztec Empire. In the first century of Spanish rule in Mexico, 1500-1600, Central and South Americans died by the millions. By 1650, 85% of Mexico's population had decline. This goes to show that disease was not only a problem in Europe during the Renaissance.