The Caduceus: The Mistaken Meaning of the Medical Symbol

Whoever started putting the ancient Greek icon on American public health officers’ uniforms had it confused with another snake-and-staff symbol.

The caduceus is used as a medical logo, but that’s not its original meaning.
The caduceus is used as a medical logo, but that’s not its original meaning. | saemilee/DigitalVision Vectors/Getty Images (caduceus); enjoynz/DigitalVision Vectors/Getty Images (background)

The caduceus is the “Born in the U.S.A.” of Greek iconography: Everyone seems to think it stands for something it doesn’t. 

This ancient symbol, also called the Staff of Hermes, depicts two snakes intertwining around a stick that is capped by wings. You’ve likely seen it on the logos of the U.S. Army Medical Department [PDF], the Office of the Surgeon General and Commissioned Corps of the U.S. Public Health Service, and some medical professional associations and health-related businesses. But for almost all its roughly 5000-year history, the caduceus had nothing to do with medicine

In Greek mythology, Hermes was the messenger of the gods, gliding between the worlds of humanity and immortality on his winged sandals. He was also the class clown of the 12 Olympic gods, the frenemy of his half-brother Apollo, and the guide who ushered souls into the afterlife. Among his inventions were fire, the alphabet, and (perhaps less impressively) dice. Hermes was also the god of trade, wealth, language, thieves, and travelers, and in his spare time, he was one hell of lyre player. 

In many visual depictions, Hermes carries the caduceus staff. In some myths, it was a gift from Apollo, exchanged for a lyre made from a turtle shell. In others, it commemorates an incident in which Hermes stopped two serpents from fighting with the touch of his staff, a symbol of the messenger god’s power as a peacemaker. The actual design may just be a carryover from the iconography of serpent worship that dates back to the dawn of civilization.

In the centuries following the heyday of ancient Greece, the caduceus endured as a symbol of travel and commerce, two subjects under Hermes’s godly domain. The icon was worked into emblems of the customs departments of China, Bulgaria, Russia, and other countries.

In the U.S., the caduceus took on a brand new meaning. Its misuse as a medical symbol seems to date to 1902 when it was added to the uniform of the United States Medical Corps. Someone in the corps may have confused the caduceus with the Rod of Asclepius, the signature walking stick of the actual Greek god of medicine, which took the form of a wingless staff with a single snake wrapped around it. While the caduceus made its way to other American military and government offices related to medicine, the Rod of Asclepius can be found on the flag of the World Health Organization and the blue Star of Life that has become a cross-cultural symbol of emergency medical providers, plus countless emblems of national medical agencies. 

But for the U.S., one of the world’s most flamboyant and image-conscious countries, it surely makes sense to use the cooler-looking symbol. Its ancient origin as an icon of commerce seems fitting for the nation with the most expensive healthcare on Earth. 

Discover More Origins of Symbols and Sayings: