Three major areas have advanced in our management of pain patients: (1) better syndrome definition, (2) clearer scientific basis for the use of analgesic medications, and (3) correct utilization of pain centers.
Acute pain1 is linked in time, location, and severity to an underlying lesion. Chronic pain can be divided into nociceptive (related to tissue injury) and non-nociceptive (deafferentation and psychogenic).2Nociceptive pain is the most common type in cancer and other medical illness. It most often responds to treatment of the underlying cause or to standard analgesic medication. Deafferentation pain3 is due to nervous system injury that interrupts the normal transmission of sensory impulses. Pain is ill-defined, burning, and dysesthetic and may have a component of sympathetic dysfunction with wasting, color changes, shiny skin, decreased temperature, and hair loss. If the sympathetic component is prominent, sympatholytic procedures may be indicated. Reflex sympathetic dystrophy and postherpetic neuralgia
Kanner R. Pain Management. JAMA. 1986;256(15):2112-2114. doi:10.1001/jama.1986.03380150122040