Chronic pain is persistent pain that last for weeks, months or years. For some, chronic pain is the result of an injury, like a sprained back, or an ongoing problem like arthritis. For others, chronic pain occurs in the absence of a past injury.
A 2011 Global Industry Analysts, Inc. report estimates that over 1.5 billion people worldwide suffer from chronic pain, with the incidence rate increasing with age. Most chronic pain conditions affect older adults. Common chronic pain complaints include headache, low back pain, arthritis pain, or neurogenic pain (pain resulting from damage to the peripheral nerves or to the central nervous system itself).