Pain cannot be measured like pulse or blood pressure, unfortunately. We can measure it in animals, but we cannot measure the pain of a person yet. Pain is something very subjective: the saying “Every one knows where his own shoe pinches” is very important. As a doctor, I can empathize with the patient, so I can feel the pain, I can be a partner to the pain; but in fact I need to be able to measure the amount of pain.
There are a number of internationally valid scales that can be used for this. I can evaluate the pain at least in a statistically realistic manner when the patient fills out a few of these forms which were adapted to the Turkish society. If your doctor asks you to fill out a number of forms, you must realize that it is for your own sake.