The International Association for the Study of Pain (IASP) defines pain as an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage. It may be due to an injury or the brain’s inability to process pain signals properly. Chronic pain can range from mild to severe and is present for long periods (>3 months) and is often the result of a disease that may require ongoing treatment. The most common sources of chronic pain include low back pain, musculoskeletal pain, migraines, fibromyalgia, neuralgia, cancer pain, visceral, and postoperative pain. With many chronic conditions, the cause of the pain is unknown.