The Renaissance stimulated medical practice just as it did all other European intellectual pursuits.  Physicians and scholars began to scientifically study medicine. 
 
Many began to research human anatomy.  Their discoveries corrected many of the errors that had gone undetected for centuries and were rapidly disseminated through the new invention of printing. Andreas Vesalius was the premier anatomist of this age and published many illustrations of his discoveries. 

Arabic pharmaceutical practices were studied and improved, and medicines--like laudanum--were developed to stop or reduce pain.  Some doctors began to investigate the spread of infectious diseases. 

Surgical procedures were also modernized, many as the direct result of battlefield experiences.  Surgeons began to experiment with ways to ease the suffering of their patients.  Amboise Pare revolutionized surgery when he began to use ligatures to stop bleeding wounds instead of cauterizing them with boiling oil or red-hot pokers. 
 
If you would like to learn more about renaissance medicine, the Karolinska Institute has many interesting links.