University of Pennsylvania Oct 8 2025 Acute or short-lived pain, despite its bad reputation, is usually a lifesaver. It acts as a transient negative sensory experience that helps us avoid danger. Touch a hot stove, stub a toe, or bonk your head on a low branch, and the nervous system cues up an "Ow!" Over time, the sting fades, the wound heals, but the lesson sticks. Chronic pain is different; the alarm keeps blaring long after the fire is out, and then the pain itself becomes the problem.