Pain is an unpleasant sensory and emotional experience usually produced by something that injures, or threatens to injure, the body. Pain begins with a stimulus, but is influenced by physiological and psychological factors before it becomes part of our consciousness.Although pain is something that we invariably want to escape or to stop, it serves several very important functions. Pain protects us by triggering a reflexive withdrawal from something damaging before we can suffer further injury, such as when we drop a hot pan before we sustain extensive burns. It is also a warning system that lets us know when an injury is about to occur: the burning ache in our muscles during extreme exertion warns us to stop using them. Pain forces us to immobilize or protect an injured part, such as a broken ankle, thus giving it a chance to heal. Pain also lets us know when we need to seek medical help, and teaches us what behaviors to avoid in the future.