During medieval times barbers also performed surgery and extracted teeth. They used barber poles to indicate their profession. The original barber pole had two bowls. One was on the top and held the leeches used for bloodletting. The other bowl was on the bottom of the pole and was used to collect the blood.
In France, during the middle ages when facial hair on a man was banned ,it allowed the barbers to become much more industrious and specialized in their profession.
Around 1210 there were academic surgeons of the long robe and barber surgeons of the short robe.
The red and white on Barber poles represented the bandages used, red was for bloodletting and white was for a clean bandage. The bandages were hung on a pole to dry after laundering. The wind whipped the bandages around causing them to twine together. This was the basis of the modern day barber pole design.
The barber pole indicated either a professional or a barber surgeon.
The poles were later made from wood and painted in red and white stripes.
When the United Barber Surgeon Company was formed in England, they decided that the blue and white pole would indicate a barber and the surgeon would use a red pole.
A second interpretation of the colors showed that the red color represented arterial blood , the blue color would represent the venous blood and the white was for the clean bandages. Spinning barber poles are supposed to indicate the blood flowing down.
Prior to 1950 there were only four manufacturers of barber poles in the USA. At present there is only one manufacturer of barber poles.
A barber pole like indicator is also used in computers to indicate a work in progress or the progress bar you see when you click on something and have to wait.
The basic concept of the barber pole has been used extensively in many areas, even in candy production and in space flight.