All human societies have medical beliefs that provide explanations for birth, death, and disease. Throughout history, illness has been attributed to witchcraft, demons, astral influence, or the will of the gods. These ideas still retain some power, with faith healing and shrines still used in some places, although the rise of scientific medicine over the past millennium has altered or replaced mysticism in most cases.

The ancient Egyptians had a system of medicine that was very advanced for its time and influenced later medical traditions. The Egyptians and Babylonians both introduced the concepts of diagnosis, prognosis, and medical examination. The Hippocratic Oath, still taken by doctors today, was written in Greece in the 5th century BCE. In the medieval era, surgical practices inherited from the ancient masters were improved and then systematized in Rogerius's The Practice of Surgery. During the Renaissance, understanding of anatomy improved, and the invention of the microscope would later lead to the germ theory of disease. These advancements, along with developments in chemistry, genetics, and lab technology (such as the x-ray) led to modern medicine.