As defined by the International Association for the Study of Pain, “Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.” Usually we think of pain when we get injured such as a cut or bruise. However, tissue damage in itself does not define pain; you can be shot in the leg and then run to save a friend and not know you have been shot even though there is a lot of tissue damage. You can also experience pain when you think you may have tissue damage such as having a sudden pang of pain when you put your hand on a stove burner until you realize that the stove is turned off. You can also have real chest pain when you have a broken heart (describing tissue damage) but your heart muscle itself is fine. Pain is always subjective; it is what the patient says it is.