Reflex Sympathetic Dystrophy (RSD)     Reflex Sympathetic Dystrophy is a very complicated pain problem which is characterized by severe pain and progressive physical changes that may persist long after the original injury has healed. The "injury" may be as simple as a sprained ankle. Reflex Sympathetic Dystrophy can occur after routine surgery.     RSD almost always occurs in an extremity, most often the outer aspect of the extremity such as the hand and forearm or the foot and lower leg. It can, however, also affect the extremity above the knee or above the elbow. While much more uncommon the condition can occur almost anywhere including the chest, breast, or even the abdomen.     Most patients describe the pain as a burning pain with extreme sensitivity to touch. Even clothing rubbing the affected area may cause extreme discomfort.     Reflex Sympathetic Dystrophy usually develops somewhat slowly in stages over weeks or several months. The affected area may appear swollen and feel warmer to touch due to inflammation as well as changes in surrounding blood vessels. Later, blood supply to the affected area can diminish and the area becomes cooler to touch. The skin can become shiny and there can be a loss of hair and skin tone. As pain increases there can even be a weakening of the underlying bone. Muscles can waste in the affected extremity. If untreated, an extremity can develop a contracture from disuse, which can frequently become permanent.     Bone scans can sometimes be used in the diagnosis of RSD.     This condition is very complicated and progressive and can be devastating to the individual patient and their family. The best treatment is aggressive and must focus on rehabilitation of the extremity as well as pain management. In the early stages of RSD it is preferable to use pain medicines that are also anti-inflammatory. Cortisone - like preparations are sometimes used in the short term to relieve symptoms and arrest progression of symptoms. Physical therapy is often prescribed for treatment of RSD.     Nerve blocks have frequently been used to break the pain cycle and prevent progression of symptoms. These nerve blocks are usually administered in a pain clinic setting by physicians specially trained in these techniques.     Reflex Sympathetic Dystrophy is also sometimes referred to as Complex Regional Pain Syndrome. It's exact cause is not known.