What is chronic pain? Chronic pain is an unpleasant sense of discomfort that persists or progresses over a long period. In contrast to acute pain that arises suddenly in response to a specific injury and is usually treatable, chronic pain persists over time and is often resistant to medical treatments. We have previously discussed chronic pain caused by osteoarthritis. The following are scenarios that cause chronic pain of a non-osteoarthritic nature: Chronic, Active inflammatory pain Maladaptive chronic pain Cancer pain. The treatment of the above conditions or scenarios is guided by the understanding of how the disease develops, progresses and behaves, in other words, its pathophysiology.