9. Superstition ruled much of the medieval world
Medicine during the medieval period faced not only the enemy of disease. Superstition dominated all levels of society, in all cultures. Disease and even injury were often seen as either the just judgment of God or evil works of Satan and his minions. A leading Benedictine Abbess, Hildegard of Bingen, attributed imbalances in the bodily humors to the influence of the devil, the price of the wages of sin committed by the stricken (she also believed that the efficacy of bloodletting was dependent on the phase of the moon, and that certain precious stones contained healing powers).
As Christianity expanded across Europe it encountered pagan beliefs which it often displaced only with great difficulty. Medieval doctors in Anglo-Saxon cultures often encountered patients stricken with an illness known as elf-shot. Such victims had been shot with invisible arrows, launched by invisible elves, which caused pain in the extremities of the victim. The learned physician treated the afflicted with an application of a poultice made from the leaves of feverfew, or similar plants with arrow-shaped leaves. A sudden headache was often attributed to elf-shot, as was rheumatism and arthritis pain. The best cure was of course prevention, achieved through the carrying of a visible charm to deter the invisible elves.