Many medical conditions cause pain. Think about having the flu, an ear infection, or spraining an ankle. Pain is a message that lets people know that something is wrong and needs attention. Pain is a common symptom.
Most pain is temporary, fading away as the problem is fixed. Occasionally, pain outlives its purpose and becomes "useless pain." This type of pain takes on a life of its own, and can be very debilitating. The reason for this is not always known, but there are things that can help.