Thursday, July 7, 2011

Medical Symbol Confusions: Caduceus versus Staff of Asclepius

    Many posts ago (11/10/10 -- Obituary Tells a Story, I promised you an explanation of the origin of the symbol of Medicine, the Caduceus. There is only one problem: I had the Caduceus mixed up with another symbol, the Staff of Asclepius which is the true symbol of Medicine. So if a doctor doesn't even know the symbol of her own profession, I thought that this might be an opportunity for education, as I educate myself. 


     Which is the symbol of medical care? Confused. Don't feel bad. I am a doctor and I didn't know the answer. I have certainly seen the first used to symbolize different forms of medical care, but had only a vague recollection of seeing the second symbol. The origin and use of these two symbols is quite interesting. Like most things that are very old, their story is long and convoluted, and many beliefs contribute to what is now accepted in the modern world.
     The first symbol above, two serpents wound around a staff with wings at the top is the caduceus or magical Staff of Hermes who was a Greek god, messenger of the gods, inventor of (magical) incantations, conductor of the dead and protector of merchants and thieves. It is derived from the Greek karykeion = "herald's staff", itself based on the word "eruko" meaning restrain, control. It was a symbol for the Phoenician god of Wisdom. Later the Roman god, Mercury replaced Hermes. The wings on top of the short rod may represent the wings that were often attached to the heels of Mercury, messenger of the Gods, signifying speed.
     The mythical origin of this rod is said to have occurred when Poulenc, in "Les Mamelles de Tiresias" (The Breasts of Tiresias) tells how Tiresias--the seer who was so unhelpful to Oepidus and Family- found two snakes copulating, and to separate them stuck his staff between them. Immediately he was turned into a woman, and remained so for seven years, until he was able to repeat his action, and change back to male. The transformative power in this story, strong enough to completely reverse even physical polarities of male and female, comes from the union of the two serpents, passed on by the wand. Tiresias' staff, complete with serpents, was later passed on to Hermes.
     So how did this symbol become associated with medicine? After all, Hermes is the god of commerce, eloquence, invention, travel and theft, and so was a symbol of heralds and commerce, not medicine. The words caduity and caducous imply temporality, perishableness and senility, while the medical profession espouses renewal, vitality and health. So what happened? Well, probably the use of this staff of Hermes came about because by the seventh century AD, Hermes was associated with alchemy. What is alchemy? Alchemy is an ancient tradition, the primary objective of which was the creation of the mythical "philosopher's stone" which was thought to be able to turn base metals into gold, and also act as an magic potion that would confer youth and immortality upon its user. Those who studied and knew alchemy were said to practice the Hermetic Arts. Initially alchemy preceded modern science and chemistry. However, alchemy also included various non-scientific mystical and occult concepts, theories and practices. Then gradually alchemy came to mean not only chemical processes but medical and pharmaceutical procedures, as even metallurgy and mining.  The staff of Hermes represented these processes as well as Mercury's messenger functions. Therefore it also became a symbol for the printing trade when it first advanced in the 14th and 15th century, because the printers liked to think of themselves as disseminators of knowledge (messages). By the 17th century and 18th century this symbol was used for all alchemical processes in all of these fields. Into the modern arena, the staff of Hermes began to represent many occult practices as well. To this day a form of the staff of Hermes, called the Caduceus Power Wand can be purchased from occult, new age, and witchcraft stores.

    Pictured left is this modern occult use of the staff of Hermes. The central phallic rod is said to represent the masculine and it is wrapped by a twisting and turning shakti (female) energy of two coupling serpents. Also occult explanations say that the rod is the spine and the tapes represent the serpents which conduct spiritual currents in a double helix pattern from the chakra at the base of the spine to the pineal gland in the brain.
     But the great mistake that sealed the Staff of Hermes' use in medicine came when the United States Army began using it to represent its medical corps in 1902. World War I guaranteed that this insignia was well disseminated. Since that time, many medical organizations, large clinics, as well as pharmaceutical companies have used this symbol in their logos.
     Walter Friedlander performed a study of 242 logos of American medical organizations. He found that typically the Caduceus was used most commonly by medical organizations that are commercial, such as large commercial hospitals and clinics, drug companies, etc. Medical organizations that are professional such as the Canadian Medical Association, the New Zealand Medical Association, and the World Health Organization are more likely to use the second symbol above, the Staff of Asclepius, perhaps because they are often organizations of doctors and perhaps have better knowledge about the origin of both symbols.

     So what is the origin of that second symbol, the Staff of Asclepius? Aescepius is described in Homer's Iliad as a healer or physician who practiced in Greece probably about 1200 BC. He was so respected that he was sometime later turned into the God of Healing. He is usually pictured as bearded, dressed in a robe that does not cover his chest, holding a staff, that is a rough hewn piece of tree limb, with a single serpent wrapped around the wood, head at the top. A similar symbol appears on a known Sumerian vase from about 2000 BC thought to represent the Sumerian God of Healing Ningishita.
     The mythical origin of Asclepius is as follows:
 Asclepius is the god of Healing. He is the son of Apollo and the nymph, Coronis. While pregnant with Asclepius, Coronis secretly took a second, mortal lover. When Apollo found out, he sent Artemis to kill her. While burning on the funeral pyre, Apollo felt pity and rescued the unborn child from the corpse. Asclepius was taught about medicine and healing by the wise centaur, Cheiron, and became so skilled in it that he succeeded in bringing one of his patients back from the dead. Zeus felt that the immortality of the Gods was threatened and killed the healer with a thunderbolt. At Apollo's request, Asclepius was placed among the stars as Ophiuchus, the serpent-bearer. The children of Asclepius included his daughters Meditrina, Hygeia and Panacea who were symbols of medicine, hygiene and healing (literally, "all healing") respectively. Two of the sons of Asclepius appeared in Homer's Illiad as physicians in the Greek army (Machaon and Podalirius).

     Medical schools developed in Greece and later spread to Rome. These locations, called Asclepions (Asclepiae) usually included a temple from which to worship Asclepius, as well as buildings to house the priests/physicians, called Asclepiadae; and buildings to house the patients. People came to believe that just by sleeping in an Asclepion, they could be healed. The practices of the local priests added an additional attraction. The people who came to these places were usually well off and offered gifts and sacrifices to the God Asclepius as well as gifts to the priests. Snakes in honor of the God were kept here. They were harmless, usually the species called Elaphe longissima. Many escaped and still thrive in the locations of the ruins of these Asclepions. There were active Asclepions under Roman rule as late as the 6th century AD.

    The staff of Asclepius was also used as a printers symbol, often used on the frontispiece of pharmacopoeia that date to the 15th and 16th century. The Caduceus and the staff of Asclepiu were used interchangeably for this purpose and that may explain some of the confusion. Many people still today (me included) use the word Caduceus to indicate both symbols.

     The actual medical origin of the staff of Asclepius is quite interesting. This may be the practical meaning of the "serpent" wound around a stick. In tropical areas, there is a parasite known as the guinea worm, Dracunculus medinensis, also called "the fiery serpent"  or the dragon of Medina. Infestation with this worm is called dracunculiasis. The life cycle of this worm involves only the human and a small water flea or crustacean. The water flea ingests the smaller larvae of the roundworm. People ingest the water flea when they drink contaminated water. The water flea is digested releasing the roundworm larva which migrates through the body, maturing and then migrating subcutaneously and growing quite long. The male is the size of spaghetti and can grow to 2 to 3 feet long. Eventually by gravity it usually moves to the lower extremities leading to inflammation and pain. Eventually they would grow to maturity and emerge from the host by eating a hole in the skin. The whole process especially the latter caused a fierce burning pain that disabled the victim from work until finally the worm would emerge and the track and emerging hole would heal up. The pain is so great in the end that people would go into the cool water of ponds or streams to relieve the pain. The water then triggers the female roundworm to release her larva into the water, contaminating it and beginning the worm's life cycle all over again. Though not life threatening, a sufferer from dracunculiasis would lose a lot of days of productive life and the emergence was often timed during the key farming season. Where endemic, so many people were infected that sometimes the harvest could not be completed contributing to hunger and societal disruption. Hence if people could afford it they went to physicians who would treat this worm. The treatment consisted of making an incision in the skin just ahead of the progress of the worm. When the worm began to emerge, the physician would wind it around a stick and exert slow tension (over days' time) and gradually wind the worm up until it was removed from the skin. If too much or rapid tension was applied, the worm would break and removal would be much more difficult and painful. The worm was very common so physicians who were knowledgeable in this procedure hung an image of the worm wound around the stick in front of their place of business.
     Interestingly, the current National Geographic Magazine has a one page article demonstrating that through education alone, the guinea worm is going the way of smallpox. People in endemic areas have been taught to drink water through a simple straining straw, or to filter it, or add an larvacide to the water before drinking. Also people who have guinea worm emerging have been taught not to go into the water to relieve pain but instead to take some anti inflammatory medications and/or seek medical treatment. Since we humans are the only hosts for this worm to mature, these two practices are eliminating the worm. Now only 4 African countries continue to see guinea worm and even those infections have become much less significant. This is the only time that a disease will likely be totally eliminated without the use of vaccines or antibiotics.

     So now you know the difference between the Caduceus and the Staff of Asclepius. You know that the true medical symbol should be the Staff of Aesclepius, though an insignia that champions Hermes, the god of commerce, might symbolize portions of the practice of medicine today. Following is a frieze that depicts the confusion between these two symbols.

Hermes (Mercury) and a merchant approach a disapproving Asclepius (Physician) and  his daughters, the naked Graces (Meditrine, Hygeia and Panacea)
[Engraved from an original in the then Museum Pio Clemens in Rome
Galerie Mythologique, Recueil de Monuments by Aubin Louis Millin, Paris 1811.]

Asclepius dealt with patients - merchants make deals with clients

Asclepius is linked with a constellation of idealistic medical ideas

Hermes is linked with hermetic occultism

Mercury is identified with mercantile mercenary views


  1. Thank you for posting your research results, very interesting.

    There is another reference to healing, snakes, and staff, found in the old testament of the bible.

    Numbers 21:6-9

    6 And the Lord sent fiery serpents among the people, and they bit the people; and much people of Israel died.
    7 Therefore the people came to Moses, and said, We have sinned, for we have spoken against the LORD, and against thee; pray unto the LORD, that he take away the serpents from us. And Moses prayed for the people.
    8 And the LORD said unto Moses, Make thee a fiery serpent, and set it upon a pole: and it shall come to pass, that every one that is bitten, when he looketh upon it, shall live.
    9 And Moses made a serpent of brass, and put it upon a pole, and it came to pass, that if a serpent had bitten any man, when he beheld the serpent of brass, he lived.

    1. I myself think the medical emblem would best be based upon the staff of Moses (& am sensing that it was, far back) rather than on Greek gods or goddesses. // I'm seeking a logo design for an organization we're calling, "Doctors for Civilization-Reason-Hope-Healing-&-Sanity in this World." -- Join us! -- including your ideas for an emblem-logo & banner.

      And I must admit .. before studying its origins, I did (and still do a bit) like the caduceus especially the Wings -- If we use wings in our emblem, maybe they can be seen as angels' wings? And .. two snakes Are more "impressive" or meaningful? than one .. One could mean Unity, two might mean the conflicts we hope to help heal .. Are we stuck back with the regular caduceus? .. if so with different meanings to it ..

  2. Thank you for commenting. I would welcome more comments on my blogs. I had read briefly about the above reference but did not include it because my knowledge of it was so inadequate. I did not know the above verse reference in Numbers. Interesting. It sure sounds like this is the Staff of Asclepius. Did healers know about the treatment of guinea worm back in the time of Moses and so form this medical idea into a religious idea? Or did the mythical Staff of Aesclepius and this symbol from the time of Moses arrise interchangeably to represent healing? It sounds like the description in Numbers does actually describe a disease. I thank you so much for this reference! It certainly adds to the whole picture of these symbols.

    1. Actually, there is some intriguing history behind the Rod of Asclepius. If you trace his origins back, Asclepius (also called the "great physician" and the "savior") is just another name used for Tammuz. During the tower of Babel era, when the groundwork was laid for pagan worship of heathen gods and goddesses, Tammuz was the counterfeit of Jesus Christ. Asclepius eventually took this roll and his symbol was this rod (which actually traces back to the Tree of Knowledge of Good and Evil, and Satan's original deception - also the origin of the Caduceus).
      If you compare the stories, it does not originate from Moses' brass serpent(Num. 21:8)[Though the devil loves for people to credit it back to God like that]. The serpent is usually the symbol of sin and Satan, but in the story of Moses' serpent it represents Christ (John 3:14) because Christ became sin for us (2Cor. 5:21) The healing power was not in the image of the snake, it was in the faith exercised in the Word of God in looking to Christ for healing from the venom of sin and Satan.
      Later, the Israelites credited the healing power to the image and turned it into an idol - which called for its destruction (2Kings 18:4).
      This is the same thing that man has done today with modern medicine -make up for their lack of faith by trusting in poisonous drugs, which are Satan's counterfeit of the Tree of Life. The Tree of Life did not have "side" effects. Drugs all list "side" effects that range from "rashes to death" - and Christ is not the author of Death.
      Study it out, everything that we are experiencing in the world today, has already been revealed in the Bible. History takes an amazing turn when compared to the light shining from the Word of God.

  3. I have read so many articles regarding the blogger lovers but this article is really a
    fastidious article, keep it up.

    Here is my blog

  4. Thanks for your enlightening article. It is interesting to know that many doctors cannot clearly distinguish the symbol of their profession or understand the origin of this symbol. I am a fresh graduate of medicine and I was particularly drawn to the caduceus as the symbol of medicine over the staff of aesculapius. I took note of the difference, and thanks to you I can now clearly differentiate, but what I want to point out is the fact that I was drawn to the caduceus solely because of its superior aesthetics (from my point of view). I think I am not alone in this and I hope that the current world trend of interest in superficiality instead of true meaning and values that has permitted the displacement of the correct symbol does not dilute the efficiency of this noble profession.

  5. Thank you Anonymous doctor! I enjoyed writing this piece and I had no idea that it would be so popular. Apparently there is not a lot of writing on the Internet at least in one place that puts the history of the symbol all together. Thank you for your last thought. I hope so too.

  6. Beautifully written piece of information which I can bet >90% medicos would be unaware of.
    Thanks a lot