Complex regional pain syndrome is a rare, chronic, and sometimes progressive condition. It involves a severe, burning pain, inflammation, and changes in the skin. It affects one of the arms, legs, hands, or feet.
The exact cause is unclear. Symptoms may appear after an injury or surgery, but often there is no injury and no sign of neurological or physical damage to the affected area.
Treatment usually includes a combination of physical therapy and medications. It is most effective if it starts soon after symptoms appear.
People with mild symptoms may not report them, so it is unclear how many people are affected.
CRPS can affect people of any age, but it usually appears between the ages of 40 and 60 years, more commonly among females.