Acute Pain is a normal sensation triggered in the nervous system to alert you to injury or the possibility of injury and the need to take action to protect and care for yourself. Chronic pain, on the other hand, persists for three to six months or more than the normal healing time of an injury. Chronic pain may originate from an initial trauma or injury, or there may be an ongoing cause of pain. However, some chronic pain may occur in the absence of any past injury or evidence of body damage.