Pain is a universal human experience. However, due to its inherent subjectivity, it is challenging to be understood. This uncertainty naturally causes problems in the field of healthcare when a patient complains of pain. Hence, efforts have been made over the past century to quantify and measure this feeling.
There was a time in the 19th century when scientists would use horse hair to measure pain by pressing it on a subject’s skin and recording the amount of pressure it took for the person to feel pain. This technique known as Schmerzpunkte is still used today to measure skin sensitivity using Von Frey filaments, named after the original scientist. Another more terrifying machine used to measure pain is a dolorimeter. This machine applies heat to a subject’s arm and is powerful enough to cause second-degree burns. In one controversial experiment, the device was used to administer pain to women giving birth, after which the women were asked to compare the pain from the machine with the pain of childbirth.
Since the 1950s, scientists and doctors have moved away from studying pain inflicted on test subjects to studying the pain already felt by them. Questionnaires and deceptively simple picture scales were introduced to record this pain. The scale usually comprises a series of cartoon faces which look increasingly distressed or a simple number line, and patients are asked to point to where their discomfort lies from no pain to worst pain. Separate nonverbal scales are also available for impaired adults or very young children. This simple pain scale has proven to be effective since then and is widely used today in modern healthcare practice.