How to measure pain is a great challenge to those who desire to control adequately such a complex experience. Standardized instruments that take into consideration the patient's own account, have been developed in order to make such a task easier. In this article we carry out a revision of the instruments used mostly for measuring postoperative pain, and we point out some of the advantages and disadvantages. We emphasize the need for specific research focusing on the measurement of surgical pain, taking into consideration the multiple dimensions of a painful experience.
category estimation; multidimensional scaling; unidimensional scaling; postoperative pain