Flagging the pain: preventing the burden of chronic pain by identifying and treating risk factors in acute pain.

Chronic pain represents a major public health problem that impacts negatively on quality-of-life issues and healthcare costs. Unrelieved acute post-traumatic and postoperative pains are risk factors in the development of chronic pain, although psychological and environmental factors are at work as well. Flagging pain (blue, yellow and red flags) helps to identify risk factors in acute pain that need attention to avoid the transition from acute postoperative pain to acute persistent and then on to chronic pain. This offers a unique opportunity for preventative medicine.