Mayo Clinic Proceedings Home

Medical Symbols: The Caduceus

      The caduceus, a staff with two snakes coiled around it, is the official insignia of the United States Medical Corps, Navy Pharmacy Division, and the Public Health Service. The caduceus is also the magic wand carried by Hermes (the Romans knew him as Mercury), the messenger of the gods.
      The caduceus probably was first used as a medical emblem in the 16th century. In its earliest form, the caduceus appeared as a forked rod, the prongs knotted or crossing to form a loop. Later, the rod was entwined by two snakes with their heads meeting at the top. Legend states that Hermes discovered two snakes fighting and thrust his rod between them. The snakes stopped fighting and wound themselves around the rod. Thus, this combination became the sign of settlement of quarrels.
      A more scientific explanation has also been given. Before the appearance of the caducei in classical Greece, the symbol seems to have existed among the Assyrians, Hittites, and Phoenicians. The Greeks, trading with the Phoenicians, probably knew of the Phoenician caduceus and of its association with the Phoenician gods. The Phoenician caduceus may have been based on a military weapon.
      Another explanation is based on the Egyptian winged disk and its influence on other ornamental forms. This symbol became prevalent throughout Asia Minor as far as Mesopotamia. The caduceus in its latest form bears most of the features of the winged disk at the end of a staff.
      The caduceus is also a symbol of peace and commerce. The present form is the result of a series of elaborations of earlier forms. In ancient Greece, the caduceus was carried by messengers and heralds, apparently serving to protect the bearer by indicating that he was engaged in a peaceful mission. Originally, the caduceus may have been an olive branch with three leaves, an important Greek symbol of peace.
      To understand the association of the winged caduceus and the healing arts, one must consider two early forms of worship—adoration of serpents and of the sun. Serpent and sun worship are found to be universally associated. The serpent was worshipped as a symbol of life and regenerative power by primitive humans, who also associated sunshine with the blessings of life and health. The establishment of the seat of serpent worship in northern Egypt, in the dominion of the sun god Ra, led to the association of the sun and the serpent.
      The caduceus has been featured on numerous stamps issued by many different countries. An example is this stamp issued by Australia in 1957.