Why is the medical symbol a snake on a stick?

The medical symbol of serpents wrapped around a staff is a familiar one in the field, decorating pharmaceutical packaging and hospitals alike. Snake bites are generally bad news so the animal might seem ill-fitting as the symbol of the medical profession, but the ancient emblem actually has quite a story behind it.

There are actually two versions of the symbol. The winged version is known as a caduceus and the stick is actually a staff that was carried by the Olympian god Hermes. In Greek mythology, Hermes was a messenger between the gods and humans (which explains the wings) and a guide to the underworld (which explains the staff). Hermes was also the patron of travellers, which makes his connection to medicine appropriate because doctors of the olden days had to travel great distances by foot in order to visit their patients.

In one version of Hermes' myth he is given the staff by Apollo, who was the god of healing among other attributes. In another version, he receives the staff from Zeus, the king of the gods, and it is entwined with two white ribbons. The ribbons were later replaced by serpents, as one story tells that Hermes used the stick to separate two fighting snakes, which then coiled around his staff and remained there in balanced harmony.

The Greek God, Hermes, is often depicted with the cadaceous. (Image credit: Getty)

Another, earlier depiction of the medical symbol is the staff of Asclepius, though it has no wings and only one snake. The son of Apollo and the human princess Coronis, Asclepius is the Greek demigod of medicine. According to mythology, he was able to restore the health of the sick and bring the dead back to life.

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In one telling, Zeus killed Asclepius with a thunderbolt for disrupting the natural order of the world by reviving the dead, while another version states that Zeus killed him as punishment for accepting money in exchange for conducting a resurrection. After he died, Zeus placed Asclepius among the stars as the constellation Ophiuchus, or "the serpent bearer."

The Greeks regarded snakes as sacred and used them in healing rituals to honor Asclepius, as snake venom was thought to be remedial and their skin-shedding was viewed as a symbol of rebirth and renewal. Which is a good thing to keep in mind the next time you spot a medical alert bracelet featuring the seemingly sinister serpents.

Additional resources

Learn more about the Red Cross international charity, about the 12 Olympians of the Greek pantheon of gods, and take a look at this huge range of medical symbols, old and new. 

Bibliography

• M Prakash and J. Carlton Johnny: Things you don’t learn in medical school: Caduceus
• Ekrem Güner, Kamil Gokhan Seker, Dr. Sadi Konuk, Sebnem Izmır Guner: Why is the Medical Symbol a Snake?
• Anil Shetty, Shraddha Shetty, Oliver Dsouza: Medical Symbols in Practice: Myths vs Reality

Updated by Livescience editor Ben Biggs on 11 March 2022.