Signs and symptoms of complex regional pain syndrome (CRPS) are similar for both types of the disorder. They may vary in severity and duration from patient to patient. The most common symptom is intense pain, which is often described as a burning sensation. Usually pain is out of the ordinary and seemingly not compatible with the clinical signs. In many patients the affected limb feels as if it is immersed in boiling water.

The skin is greatly affected by CRPS. Sensitivity and tenderness of the skin may increase, and changes may occur in skin temperature, color and texture (such as skin thinning or appearing shiny). The skin may alternate between being sweaty and cold, and skin color may range from white and blotchy to red or blue.

In addition to leg pain and arm pain, symptoms include:

• Pain caused by normally nonpainful stimuli (allodynia)
• Extreme sensitivity to pain (hyperalgesia)
• Changes in growth of hair and nails
• Joint stiffness, inflammation and damage
• Muscle spasms and weakness, and loss of muscle (atrophy)
• Decrease in range of motion of the affected body part
• Tremors in the affected limb
• Depression, anxiety and sleep disturbances

CRPS can be treated far more effectively when it is detected early. Left untreated, it can progress to more serious signs and symptoms. Patients should consult a physician if they experience constant, severe pain that affects a limb when it is touched or moved, or if they have trouble moving a limb because of stiffness. Such symptoms may indicate that the skin and muscles are beginning to atrophy.

Patients may also experience tightening of muscles as they lose tone. This can result in a condition in which the hand and fingers or foot and toes contract into a fixed position.