In Western Europe fall down of Roman imperial authority led to a halt to the development of organized medical practice. Medicine became localized, with folk-medicine supplementing what remained of the medical knowledge of antiquity. Medical knowledge was conserved and practiced in many monastic institutions, which frequently had a hospital attached. Organized professional medicine re-emerged, with the basis of the medical college of Salerno in Italy in the 11th century, which in co-operation with the monastery of Monte Cassino, rendered many Byzantine and Arabic works.

In the 12th century universities were founded in Italy and elsewhere, which shortly developed schools of medicine. Slowly the reliance on the masters of the ancient world was supplemented by the results of individual surveillance and experience. Surgical practice improved greatly during the medieval period. With the rebirth came an increase in experimental investigation, principally in analysis and examining bodies. The work of individuals like Andreas Vesalius and William Harvey challenged believed folklore with scientific evidence. Understanding and analysis improved but with little direct advantage to health. Few effective drugs existed, past opium and quinine, folklore cures and potentially poisonous metal-based compounds were popular treatments.