Normally, when someone gets injured, time heals the wounds and pain goes away.  But patients with Complex Regional Pain Syndrome (CRPS), also known as Reflex Sympathetic Dystrophy Syndrome (RSD), don't heal that way.  Instead, their pain gets worse instead of better and may even spread beyond the injured area.

Complex Regional Pain Syndrome is a chronic pain condition that causes severe, non-stop pain. According to the Reflex Sympathetic Dystrophy Syndrome Association (RSDSA), CRPS or RSD affects between 200,000 and 1.2 million Americans.  It's more common in women than men and the average age of onset is 42 (though there are increased reports of occurrence in young women and children).

CRPS is caused by malfunction of the nervous system that sometimes develops in response to an injury, accident or medical procedure. Nerves send constant pain signals to the brain, even after the injury appears to have healed.  Sometimes, all it takes is a minor injury like a sprain to trigger CRPS. One of its key characteristics is that the pain response seems exaggerated in relation to the severity of the injury.  For example, on a scale of one-to-ten (one is almost no pain and ten is excruciating), the injury might be expected to elicit pain at around a level 4 but instead, the patient feels it as a nine or ten, and that number doesn't go down with healing.

The National Institute of Neurological Disorders and Stroke explain that CRPS most often affects one area of the arm, leg, hand, or foot, but the pain might then spread to include the entire arm or leg. 

Typical features of CRPS include dramatic changes in the color and temperature of the skin over the affected limb or body part, accompanied by intense burning pain, skin sensitivity, sweating, and swelling. 

If the damaged nerve isn't able to regulate blood flow, sensation and temperature to the affected area, this can cause damage to blood vessels, bones, other nerves, muscles and the skin and if untreated, can cause permanent and visible damage, like immobility and muscle wasting.

RSDSA says there are two types of CRPS:

  • CRPS Type I - where the nerve injury cannot be immediately identified
  • CRPS Type II (also referred to as Causalgia) - where a distinct "major" nerve injury has occurred.

Doctors don't know yet what causes CRPS but research is studying how the sympathetic nervous system and immune system may be connected to development of CRPS.

There's no specific test for diagnosing CRPS, but doctors may prescribe:

  • Tests that show temperature changes and lack of blood supply in the affected area
  • Bone scans
  • Nerve conduction studies
  • X-rays

Most patients see, on average, five different physicians before being correctly diagnosed with CRPS.  While CRPS is not a psychological disorder, many patients experience anxiety, depression and other psychological symptoms associated with their disease; especially if doctors, family and friends don't believe they're in pain.

There's no cure for CRPS but there are ways to relieve pain and prevent permanent damage.  Treatment includes pain medication, physical, occupational and psychological therapy, nerve blocks and spinal cord stimulation.  Prognosis varies among individual patients but those diagnosed in early stages of CRPS tend to do better than those diagnosed later. 

If you are experiencing symptoms similar to CRPS, talk to a neurologist about diagnosis and treatment options.


National Institute of Neurological Disorders and Stroke

NINDS Complex Regional Pain Syndrome Information Page

Reflex Sympathetic Dystrophy Syndrome Association