According to the IASP (International Association for the Study of Pain) :" Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage". According to WHO, assessment is necessary in every situation that involves pain, excluding pain that is life threatening. Valid and reliable assessment is essential for effective pain management. The very nature of pain makes it impossible to measure objectively. There are different types of pain, and as caregivers, we need to diagnose the pain accurately in order that each patient gets the most effective treatment and continued evaluations, as needed. When caregivers decide on a treatment for pain, they are relying on the relatively objective VAS (Visual Analogue Scale.) According to recent studies most patients were dissatisfied with the pain treatment they had received. Approximately eighty percent of patients who present to emergency departments worldwide come because of pain.