The Caduceus vs. Staff of Aesculapius - One Snake or Two?

There is much confusion of the true symbol of medicine. The single staff with one snake-entwined is the current American Medical Association logo. The histor y of this ancient symbol with a heritage stretching over two millennia is shrouded in the fog of history.¹ Many physicians as well as the public are unaware there are two distinct symbols commonly used which have two different origins. For example in a 2014 survey in India revealed that only six percent of physicians knew that the Staff of Aesculapius was the true symbol of medicine.²

Aesculapius was the god of medicine and was the son of Apollo, the god of healing (Figure 1). The Staff of Aesculapius is a rough-hewn branch representing plants and growth entwined by a single snake. Aesculapius was known as the god of medicine. He was killed by his grandfather, Zeus, with a thunderbolt because not enough people were passing onto the underworld due to his healing skills.^{3, 4}

Figure 1.

Aesculapius, god of Medicine, was the son of Apollo, the God of Healing.

Hermes (Mercury) was the messenger of the gods and known for carrying a staff known as the Caduceus. The caduceus included two snakes topped off with a set of wings. The Caduceus is from the Greek root meaning “herald’s wand” and was a badge of diplomatic ambassadors associated with commerce, eloquence, alchemy, thievery, and lying.⁵

The popularity of the caduceus with two snakes is probably attributed to being more aesthetically appealing than the single snake on the Staff of Aesculapius (Figure 2). The symmetry is more balanced than the single snake.⁴ The caduceus if often used in medically related industries such as pharmaceuticals and hospital supplies.

Figure 2.

Two wings and two snakes are the difference in the Caduceus (left) and the Staff of Aesculapius (right).

The snake is a powerful symbol.⁵ The ancients looked on the snake as a symbol of health and healing because it could shed and regenerate its’s skin. The snake also produced venoms which killed many parasites in the body. Many patients suffering from sickness such as depression were put into a temple healing rooms containing snakes to shock them out of their stupor.

Hippocrates of Kos was a physician the father of Western Medicine, ca. 450-380 BCE. It was believed that Hippocrates was a direct descendant of Aesculapius. Hopefully, most of you know the Hippocratic Oath begins with the words “I swear by Apollo, the physician, and by Aesculapius….”

The question to ask is how did the caduceus become popular so quickly in the United States? The role of the United States Army Medical Corps (USAMC) is crucial. In 1902, at the suggestion of an assistant surgeon, Captain Frederick Reynolds, a new uniform code was established, and the caduceus became a collar insignia for all personnel in the USAMC. From Captain Reynold’s correspondence with the Surgeon General’s office, it is apparent that he was unaware of the distinction between the caduceus and Aesculapius. He recommended the combined use of the “cock of Aesculapius” and the caduceus. His statement to the Surgeon General that the Medical Corps of “several foreign powers, notably the English” all displayed the caduceus was also erroneous. In fact, no other western medical military ser vice of that time displayed the caduceus; they all used the Aesculapius symbol. Medical Associations in Asia, India, Canada, Great Britain, France, Germany, Africa, and Scandinavia all share the Staff of Aesculapius.

Thus, the adoption of the caduceus by the USAMC seems to have been simply a misunderstanding of classical mythologic iconography.² Ironically, this mistake was nearly avoided. In March 1902, when Captain Reynolds initially suggested the switch to the caduceus symbol, the Surgeon General, G.W. Sternberg, dismissed his request outright. However, Captain Reynolds was persistent and, later that year, he sent a second letter to the new Surgeon General, W.H. Forwood; this time, his proposal was approved. Thus, on 17 July 1902, the “caduceus of gold” was adopted as the branch insignia of the USAMC. This mistake did not go entirely unnoticed. In 1917, Lieutenant Colonel McCulloch, the librarian to the Surgeon General, discovered original documents showing that the coat of arms adopted by the USAMEDD a century earlier had displayed the Aesculapius and not the caduceus. McCulloch lamented the error, but did nothing to correct the error.² The U.S. Army Medical Corps and the U.S. Navy Medical Corps still use the caduceus with the two snakes. The U.S Air Force Medical Service uses the Staff of Aesculapius with one snake.

In conclusion:

The Staff of Aesculapius has represented medicine since 800 BCE, and most knowledgeable medical authorities support its use as the symbol of medicine.

The New England Journal of Medicine, The American College of Physicians, and the World Health Organization use the Staff of Aesculapius.

The Staff of Aesculapius has represented medicine since 800 BCE and most authorities support its use as the symbol of medicine.

The Staff of Aesculapius is the only true symbol of medicine.