Muscle pain can be caused by a variety of factors. It can be due to overuse of muscles, muscle fatigue, a sprain, overexertion of muscles, and much more. Joint pain can be caused by a rash, a fever, a viral infection, a broken bone, tendinitis, and much more. Joint pain is commonly found in places like the heel, the shoulder, the elbow, or the neck. Nerve pain is usually associated with a chronic pain condition or a direct injury. This can be caused from complex regional pain syndrome, a surgical procedure medical error, multiple sclerosis, stroke, carpal tunnel syndrome, cancer, and diabetes.