Medicine is the scientific and professional discipline dealing with the study, diagnosis and treatment of disease and injury. In modern times, the practice of medicine is largely limited to licensed physicians, a profession which now includes surgeons, a group that until the early 20th century was treated as a separate skilled profession.
The roots of modern medicine go back to Greek times, where many of today's diseases were named and introduced. The symbol of the profession, the caduceus or staff surrounded by two serpents, dates to this period. Famous physicians of the time included Celcus, a Roman who was one of the leading diagnosticians of his day, and Hippocrates, a Greek physician who developed the Hippocratic Oath.
After the fall of Rome, most medical knowledge was saved by the Arabs, who by the turn of the first millennium had spread it throughout Europe, North Africa and West Asia. However, Arab medicine did not change greatly, and it was only during the European renaissance that medical knowledge again started to move forward, primarily due to the European practice of dissecting dead bodies, which brought knowledge of internal anatomy and, later, the circulatory system. After that, European medicine started to advance more quickly than the medical tradition in most parts of the world.
However, the profession was largely split into three major practicing groups, physicians, surgeons and barber-surgeons, each with their own specialized medical practices. It was only in the 19th century that developments in medical science started to remove many of the barriers between the professions, and eventually relegated barber-surgeons (who were generally only skilled in bloodletting) to history.
By the 19th century, the training of physicians became more regulated, and by the early 20th century the practice of learning the art of medicine merely by working with doctors fell out of favour in Europe and North America. At this time, it also became a crime for anyone other than a trained physician to engage in the practice of medicine.
Medicine has made rapid advances during the last 100 years, partly due to a better understanding of nutrition and sanitation, but partly through developments such as antibiotics and antiseptics.