Pain, a subjective sensation, has been increasingly studied, as it has been recognized as an important factor in patients' recovery and quality of life. Pain is charted today as one of the vital signs. For standardization, pain is charted by a number from 0 to 10 indicating its level. The most common practiced pain assessment tool today is the VAS- Visual Analog Score (facial or numerical), by which the patient himself indicates the level of the pain he or she endures. It has been found that the correlation between the reported pain by the patient and the assessed pain by the caregivers or the medical personnel becomes poor as pain intensifies.