It is relatively common, especially in the United States, to find the caduceus, with its two snakes and wings, used as a symbol of medicine instead of the correct rod of Asclepius, with only a single snake. This usage is erroneous, popularised largely as a result of the adoption of the caduceus as its insignia by the US Army medical corps in 1902 at the insistence of a single officer (though there are conflicting claims as to whether this was Capt. Frederick P. Reynolds or Col. John R. van Hoff).
The rod of Asclepius is the dominant symbol for professional healthcare associations in the United States. One survey found that 62% of professional healthcare associations used the rod of Asclepius as their symbol. The same survey found that 76% of commercial healthcare organizations used the Caduceus symbol. The author of the study suggests the difference exists because professional associations are more likely to have a real understanding of the two symbols, whereas commercial organizations are more likely to be concerned with the visual impact a symbol will have in selling their products.
The initial errors leading to its adoption and the continuing confusion it generates are well known to medical historians. The long-standing and abundantly attested historical associations of the caduceus with commerce, theft, deception, and death are considered by many to be inappropriate in a symbol used by those engaged in the healing arts.