BACKGROUND AND OBJECTIVES: Pain quantification faces special difficulties. They appear due to the obvious association of pain to a set of emotional, motivational and cultural factors. However, pain measurement is essential to evaluate and treat its effects. This study aimed at showing that psychophysical methods might be adequately used to measure both clinical and experimental pain. CONTENTS: In addition, the methodology may be useful to analyze pain mechanisms, analgesia, methodological biases inherent to pain verbal records, and to dissociate sensory and cognitive components from pain sensation/perception. CONCLUSION: The psychophysical methodology may be a trustworthy and valid measurement of the fifth vital sign, which is pain, in all its dimensions.
Clinical pain; Experimental pain; Pain evaluation; Pain measurement; Pain perception; Pain psychophysics