Knee-Complex-Regional-Pain-Syndrome-(CRPS)Overview
This is a type of chronic, long-lasting, pain. In most cases, it develops in an arm or a leg that you have previously injured. With CRPS, you may have unexplained pain that won’t go away. It may be severe, and it may spread.

Causes
We don’t know the exact cause of CRPS. It’s an abnormal response that your body has to being hurt. It seems to be a type of overreaction, almost like an allergy. It can develop after any kind of trauma, such as a sprain, a fracture, a burn or a medical procedure. CRPS may involve your immune system along with your nervous system. The genes you have inherited may also play a role.

Symptoms
If you have CRPS, you may feel burning pain, or pins and needles. The pain may spread. If you hurt your hand, for example, it may spread to your entire arm. It may even spread to your other arm. Your skin may change colors, and it may feel warm or cool. It may be so sensitive that even a light touch hurts. You may have other issues, such as abnormal sweating, a change in hair or nails, or problems moving your limb.

Treatment
Treatment for CRPS can involve physical therapy for your body and psychotherapy to help you deal with depression and anxiety. You may benefit from medications. A nerve block may help. You may benefit from a device such as a pump which can deliver medication directly into the fluid around your spinal cord as you need it. Your healthcare provider can create a plan that is right for you.