Doctors are not sure what causes CRPS. In some cases, the sympathetic nervous system plays an important role in the pain. Another theory is that CRPS is caused by a triggering of the immune response, which leads to the inflammatory symptoms of redness, warmth, and swelling in the affected area.
CRPS has two forms:
- CRPS 1 is a chronic nerve disorder that occurs most often in the arms or legs after a minor injury.
- CRPS 2 is caused by an injury to the nerve.
CRPS is thought to result from damage to the nervous system. This includes the nerves that control the blood vessels and sweat glands.
The damaged nerves are no longer able to properly control blood flow, feeling (sensation), and temperature to the affected area. This leads to medical problems in the:
- Blood vessels
Possible causes of CRPS:
- Injury directly to a nerve
- Injury or infection in an arm or leg
In rare cases, sudden illnesses such as a heart attack or stroke can cause CRPS. The condition can sometimes appear without obvious injury to the affected limb.
This condition is more common in people ages 40 to 60, but younger people can get it, too.