There were several scientists or scholars performing experiments in medieval times. One of these was Roger Bacon, a Franciscan friar, who wrote about many subjects and whose ideas included flying machines, horseless carriages and boats powered by mechanics. His ideas were not popular with everyone and he spent some of his life in prison.

Professional doctors and surgeons were practicing medicine in medieval times. In the monasteries monks would act as doctors treating other monks, travellers and people from the local communities. Herbs were widely by the monks and they grew these in herb gardens within the monastery. Blood-letting was believed to be a cure for all sorts of illness.

Leprosy is a disease that is commonly associated with the medieval period. Special hospitals were built where the lepers could be kept in isolation. Archbishop Lanfranc founded the first leper hospital near Canterbury. Many more hospitals to help lepers were built across the country following Lanfranc's example. King John also helped the suffering lepers and founded several hospitals and granted lepers special rights.