Definition of Pain
The International Association Study of Pain defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.” Pain is a prominent symptom in many acute injuries and illnesses, and often subsides as the medical condition resolves. Since such acute pain is usually short lived, it is not a problem that is considered in an impairment rating system. However, chronic pain is a problem that potentially could be the cause for an impairment rating. The definition of chronic pain is imprecise but, in a general way, it refers to pain that persists over time. For the purposes of the Guides, chronic pain is defined as pain that persists beyond the expected healing time of the medical disorder thought to have initiated the pain. For many sections in the Guides, chronic pain will be pain that persists beyond 3 months, as most common conditions affecting the musculoskeletal and other organ and systems will substantially heal in this time frame. The nervous system is a notable exception. Although any time point is arbitrary, 3 months should encompass the expected healing time in most situations where there is tissue injury but will allow for situations in which there is no expected healing time.