I am a big fan of Greek mythology and stories. I remember my dad and mom reading me the classic stories before bed when I was a kid, and recently I reread the adult versions of some of these tales. References to Greek mythology are everywhere, especially in medicine. Which reminds me...if your college offers it, take a course on medical terminology (you're the man Dr. Pluta!) - learning prefixes, suffixes, and root words of diseases and body systems is incredibly useful come medical school. Anyways, the Rod of Asclepius is one of those well-known symbols that has features of both mythology and medical history. Asclepius is the Greek god of medicine and healing. There are many versions of his story, but in art, he is always depicted with a serpent-entwined staff/rod. Asclepius was rescued from the womb of his dying mortal mother (think emergency C-section) and has daughters rather aptly named Meditrina, Hygieia and Panacea. Ironically, Asclepius' gift for healing, and even bringing the dead back to life led to his own demise. Hades was worried that with Asclepius around, no more dead spirits would come to the underworld. In an effort to prevent this, Hades had Asclepius killed.
In honor of this Greek god, a type of non-venomous snake was often used in ancient healing rituals. The Aesculapian Snakes (as they are still sometimes called) would even crawl around freely in places where the sick or injured were kept. As these snakes can be rather long, that sounds absolutely disgusting to me. Thankfully I have yet to see a snake in the hospital where I go to school.
Asclepius is even found in the first sentence little thing called the Hippocratic Oath:
Anyways back to the Rod of Asclepius, which is more famous than the guy carrying it. It is one of the most recognizable medical symbols out there. However, have you ever really thought about the symbology of it? Why a snake around a rod? Let's get our Dan Brown on...
Perhaps the grossest, yet most believable explanation for the truth behind the symbol is found in a parasitic worm. A long time ago (and to this day in less developed areas), infection via worms was a common medical problem. One such creature, cheerfully nicknamed "the fiery serpent," would crawl around just under the skin of some poor soul. The only cure was to cut it out. The worm would then crawl out through the open wound and the "physician" would position a small stick for the worm to crawl up, around, and completely out of its human host.
Other theories are just interesting, and probably not much more than thought experiments. A staff can help you stay on your feet, a snake can bite your heel and lead you to death's door. Perhaps the Rod of Asclepius shows the dual nature of medicine and those that practice it. Physicians deal with life and death, sickness and health, all on a daily basis. I like the duality theme of the symbol.
The serpent around the rod is a symbol also featured prominently in the Bible, especially in the Old Testament. There is a famous scene where Aaron, the brother of Moses throws down his walking staff and it becomes a giant snake. How exactly this fits into the overall doctor/medicine story? I am not real sure.
However, there is another odd bit from Numbers 21:6-9. Basically Moses is able to help his people by creating a bronze snake and placing it on a pole. Anyone who looks at the pole is then healed of his or her affliction. If you can't see the connection to medicine in this one, I can't help you.
I am sure that you have also seen the Caduceus, that symbol with two snakes and wings. However, it is different than the Rod of Asclepius. Its connection to double-helixed DNA, and the association with a Sumerian entity known as Ningishzida is another post all together.