Complex Regional Pain Syndrome, or C-R-P-S, formerly known as reflex sympathetic dystrophy, or R-S-D,
is a chronic condition that causes persistent burning pain and swelling in your arms, hands, legs or feet.
Your body's normal response to an injury begins when pain receptors deliver pain messages, in the form of nerve impulses, to your brain.
Once these impulses reach the pain centers in your brain, the pain centers generate new impulses and send them through your sympathetic nervous system to the area of injury.
The sympathetic impulses trigger an inflammatory response, causing blood vessels to expand.
The inflammatory response also leads to swelling and redness in the damaged tissue.
As your wound heals, the swelling and redness subside, and the pain goes away.
However, if you have complex regional pain syndrome, the pain and swelling do not go away after your wound heals, and may worsen over time.
Although the exact cause is unknown, one theory suggests that after your injury has healed, abnormal impulses continue to travel along nerves
to your skin and blood vessels, stimulating the inflammatory response.
There are two types of complex regional pain syndrome, though the symptoms are the same for both.
If you have CRPS I, your condition may have been triggered by an illness or injury, but you do not have a nerve injury in the affected area.
If you have CRPS II, your condition is clearly linked to a nerve injury in the affected area.
Treatment of complex regional pain syndrome is focused on pain management, as there is no cure for this condition.
Your treatment options may include pain medication, physical therapy, a nerve block, implantation of a pain-controlling device, surgery, and psychosocial support.