Abstract
International Association for the Study of Pain defines pain as “An unpleasant sensory and emotional tissue damage, or described in terms of such damage”. This means that pain is a completely subjective sensation. Therefore, it is very difficult to evaluate this sensation quantitatively. We must, however, try to evaluate pain in the clinical field because the evaluation of pain is indispensable for the diagnosis of diseases and the selection of treatments. Some methods to evaluate pain such as pain scales, pain questionnaire, devices for the measurement of the degree of pain, and drug-challenge test with pharmacological analysis of pain are described in this article.
