Complex Regional Pain Syndrome (CRPS)

Complex regional pain syndrome, or CRPS, is a long-term pain condition that usually affects one limb, such as an arm, leg, hand or foot. It often develops after an injury or operation, but the pain is far more severe and lasts much longer than would normally be expected for that injury.

As well as pain, the affected area may look and feel different, with changes in skin color, temperature and swelling. The condition can be distressing, but many people improve, particularly when care begins early.

The main symptom is continuous, often severe pain in the affected limb. The pain may feel burning, stabbing or throbbing, and the area can become so sensitive that even a light touch, a gentle breeze or a change in temperature is very uncomfortable.

The skin over the area may change color, becoming red, blotchy or pale, and may feel warmer or cooler than the rest of the body. Swelling, changes in sweating, and altered hair or nail growth can also occur. Some people find the limb becomes stiff or harder to move over time.

The exact cause of CRPS is not fully understood. It is thought to involve an abnormal response by the nervous system and inflammatory processes, which lead to the pain and other changes being much greater than expected.

It often follows an injury such as a fracture, a sprain or surgery, though it can sometimes appear with no obvious trigger. The severity of CRPS is not related to how serious the original injury was.

There is no single test that confirms CRPS. Doctors usually make the diagnosis clinically, by carefully assessing your symptoms and examining the affected limb, and by ruling out other conditions that could explain the pain and changes.

Tests such as scans or nerve studies may sometimes be used, mainly to exclude other problems rather than to confirm CRPS itself. Because early treatment can improve outcomes, it is important to seek medical advice promptly if pain after an injury seems far worse or longer-lasting than expected.

CRPS is usually managed with a combination of approaches brought together in a multidisciplinary plan. Physiotherapy is a key part of care, helping to keep the limb moving, maintain strength and prevent stiffness, even when this feels difficult because of the pain.

Medicines may be used to help control pain, and some people benefit from nerve blocks, where an injection is used to interrupt pain signals. Because living with ongoing pain can affect mood and wellbeing, psychological support is also an important part of treatment. Care is tailored to each person and often adjusted over time.

The outlook varies from person to person. Many people gradually improve, particularly when treatment starts early and combines physiotherapy, pain relief and psychological support. For some, symptoms can be more persistent, so ongoing support from a care team is valuable.

CRPS cannot reliably be prevented, but keeping a limb gently moving during recovery from an injury, with guidance from your care team, may help. If pain after an injury or operation is far more severe or longer-lasting than expected, speak with a doctor rather than waiting, as earlier care offers the best chance of improvement.