* Blood, Bandages, and Veins: The most common explanation is that the red represented blood, as barbers used to perform bloodletting as a medical practice. The white represented the bandages used to stem the flow of blood. Some believe the blue was added to represent veins, completing the visual symbolism of the barber-surgeon's work.
* American Patriotism: There is a theory that the blue stripe was added to the barber pole in America to show patriotism and resemble the colors of the American flag.
While the exact reason for the blue stripe remains somewhat debated, all theories point to the historical connection between barbering, surgery, and the evolving symbolism of the barber pole over time.