Causalgia is a relatively rare pain syndrome that occurs from injury to the peripheral nerves, which extend from the central nervous system (spine and brain) to the arms, legs and internal organs. Within 24 hours, those experiencing such an injury may feel a severe burning pain in the hand or foot, depending on the nerve that is damaged. Any stimulation to the affected area only worsens the pain.

Severe cases are called major causalgia, while less severe forms of the condition are called minor causalgia. The most common source of causalgia is injury to the brachial plexus , the bundle of nerves that run from the neck to the arm.

You may also experience increased or decreased blood flow due to dilation and constriction of vessels, dry and scaly skin, hair loss, changes in sweating, ridges on your finger- or toenails, coarsening hair and tapered fingers.

This condition is similar to complex regional pain syndrome .

Diagnosis of Causalgia

No specific test can diagnose this condition definitively. After taking medical history and performing a thorough physical examination, several tests may also help in the diagnosis:

  • Bone scans detect changes in the bone
  • Sympathetic nervous system tests look for disruption in nerve signaling
  • Thermography measures temperature differences across the affected limb
  • Sweat tests compare the amounts of salt chemicals in the affected and non-affected limbs
  • X-rays determine loss of bone minerals
  • Magnetic Resonance Imaging (MRI) shows any tissue changes

Treating Causalgia
Where medical therapy does not tend to be effective, our team may recommend a sympathetic block. This involves injecting a mixture of anesthetic and steroids locally to block certain signals from the sympathetic nervous system. This method (also used in diagnosis) brings at least temporary relief from causalgia. If the block does not work, we may suggest a sympathectomy, which is surgery to block these nerve signals. This procedure works in approximately 80 percent of patients.


Our physicians at Houston Methodist specialize in managing causalgia at the following convenient locations