Pain in limb is a term used to describe discomfort affecting any part of a limb or extremity (such as an elbow or knee) or the entire limb (arm or leg).The term is general in nature and could be used to describe pain that arises from various causes.isk for pain in limb is difficult to determine. As we age, musculoskeletal pain is more common. Unhealthy aging may be accompanied by both musculoskeletal and medical conditions that may generate pain. Every individual will experience some pain yearly.