Abstract: The present invention is directed toward an apparatus and method for the accurate and uniform diagnosis and/or treatment of varying forms of pain that a person is experiencing. The apparatus is a hand-held device displaying two complimentary scales on opposite faces bearing a slidable indicator that a person can use to describe the amount and intensity of the pain that he/she is experiencing. One side of the device displays a patient's pain scale that depicts a spectrum of pain ranging from no pain to unbearable pain. The other side of the device displays a provider's pain scale divided into discrete intervals identifying verbal and/or numerical pain descriptors. The slidable indicator is mounted on the device and overlays both scales on each side of the panel. The slidable indicator has an indicator line for each scale. The indicator lines are arranged such that when one indicator line is moved, the other indicator line is moved in a complimentary manner.