Complex Regional Pain Syndrome

Complex regional pain syndrome is a challenging neurological condition that causes severe, long-lasting pain—usually in an arm, leg, hand, or foot—that is far worse than expected from the original injury. While this condition can significantly impact daily life, early recognition and treatment offer the best chance for improvement and recovery.

Table of contents

• What is Complex Regional Pain Syndrome?
• Types of CRPS
• Who Gets CRPS?
• Signs and Symptoms
• What Causes CRPS?
• How CRPS is Diagnosed
• Treatment Options
• What to Expect
• Living with CRPS

Reflex sympathetic dystrophy, RSD, Causalgia

What is Complex Regional Pain Syndrome?

Complex regional pain syndrome (CRPS) is a form of chronic pain—pain that lasts a long time—that usually affects an arm or leg. The term chronic means the condition has lasted longer than three months^[2]. CRPS is uncommon, affecting about 200,000 people every year in the United States^[3], and its cause is not clearly understood^[1].

The most defining feature of CRPS is that the pain is out of proportion to the severity of the injury that may have caused it^[1][7]. What might start as a simple fracture or minor surgery can develop into intense, persistent pain that does not improve as expected. CRPS typically develops four to six weeks after an injury, surgery, stroke, or heart attack^[1][7].

Experts believe that CRPS occurs as a result of problems in your central or peripheral nervous systems. Your central nervous system is made up of your brain and spinal cord, while your peripheral nervous system carries information from your brain and spinal cord to your arms, legs, fingers, and toes. When these systems don’t work properly, they create an overreaction to pain signals that your nervous system cannot shut off^[3].

Types of CRPS

There are two main types of CRPS, though both are treated in the same way^[7]:

Type 1 CRPS (previously called reflex sympathetic dystrophy or RSD) occurs without clear nerve damage. It happens after an illness or injury that did not directly damage a nerve in the affected area. This type accounts for about 90 percent of CRPS cases^[3][7].

Type 2 CRPS (previously known as causalgia) occurs when there is known damage to a specific nerve^[3][5].

Sometimes doctors also describe CRPS based on the temperature sensation in the affected area. Warm CRPS is usually felt earlier in the condition, while Cold CRPS generally appears when CRPS has been ongoing for some time^[2].

Who Gets CRPS?

CRPS can affect people of any age, including children, but it is relatively uncommon^[4]. The condition is three to four times more common in women than in men, and the peak age when it starts is between 40 and 70 years^[7][13]. In adults, the arm is most commonly affected, while in children, the leg is more often involved^[6].

Research shows that among patients with a fracture, anywhere from 0.05 percent to 7 percent develop CRPS, depending on the study^[7]. About 66 percent to 80 percent of cases occur in people of European ancestry^[3].

Certain factors can make recovery more difficult. Smoking and diabetes can make it especially hard to recover from CRPS, as can having received chemotherapy in the past. Quitting smoking and managing diabetes can increase your chance of recovering^[2]. Younger people, children, and teenagers are more likely to recover, as are healthy older adults with good circulation and nutrition^[2].

Signs and Symptoms

The most common and prominent symptom of CRPS is pain. The pain can be constant or come and go, and it is often described as a burning, stinging, or tearing sensation. Many patients describe it as feeling like “pins and needles” or as if the affected limb is being squeezed. The pain is often deep inside the affected limb^[3][2].

People living with CRPS have pain that is much greater than normal, even without a visible injury^[2]. Patients frequently experience severe levels of pain—rating it 42 out of 50 on the McGill University Pain Scale^[18].

Symptoms typically start within four to six weeks after an injury, fracture, or surgery, but they can develop without a known cause^[3]. How severe and how long symptoms last varies greatly from person to person^[3].

Common symptoms of CRPS include:

• Continuous burning or throbbing pain, usually in the arm, leg, hand, or foot^[1]
• Increased sensitivity to painful touch—a pinch may feel more painful than usual^[3]
• Feeling pain from things that normally do not hurt, such as just touching your skin or a light breeze^[3][5]
• Numbness in some areas^[3]
• Swelling of the painful area that may come and go or remain constant^[1][3]
• Changes in skin temperature—the affected area may feel warmer or cooler compared to the opposite limb^[1][3]
• Changes in skin color—your skin may appear blotchy, pale, white, purple, red, or blue^[1][3]
• Changes in skin texture—your skin may become shiny, thin, or excessively sweaty^[1][3]
• Changes in hair and nail growth—you may have rapid growth or no growth at all^[1][3]
• Joint stiffness, swelling, and damage^[1]
• Muscle spasms, tremors, and weakness^[1]
• Decreased ability to move the affected body part^[1][3]

Symptoms may change over time and vary from person to person^[1]. Pain, swelling, redness, noticeable changes in temperature, and extreme sensitivity to touch and cold usually occur first^[1].

Over time, the affected limb can become cold and pale. It may develop skin and nail changes as well as muscle spasms and tightening. Once these changes occur, the condition is often harder to reverse^[1].

CRPS occasionally may spread from where it started to other parts of the body, such as the opposite limb^[1]. In some people, symptoms of CRPS go away on their own. In others, symptoms may persist for months to years^[1].

What Causes CRPS?

The cause of CRPS is unknown, but for many people it is thought to be the result of the body reacting abnormally to an injury^[4]. Most cases of CRPS are triggered by trauma or injury to the affected limb or other body part^[2][6].

When the body receives an injury, pain and inflammation normally result. As healing progresses, the pain and inflammation usually decrease. But with CRPS, the pain and inflammation remain and often increase. This happens due to damage to or problems with the peripheral sensory neurons—the nerve cells that carry sensory information^[2].

In more than 90 percent of cases, CRPS is triggered by nerve trauma or injury to the affected limb that damages the thinnest sensory and nerve fibers that control pain, temperature sensations, and small blood vessels^[2].

Most cases of CRPS occur after an injury to the arm or leg, such as^[6]:

• A broken bone (fracture)
• A deep wound or cut
• Surgery, such as a knee procedure or an operation to treat carpal tunnel syndrome

Occasionally, people who have had a spinal cord injury, stroke, or heart attack develop CRPS^[6]. Sometimes CRPS can happen without a clear injury^[5].

Most health professionals believe that a few different factors working together may trigger the symptoms. The way each of these factors contributes to CRPS may be different for each person^[6]. These triggering factors are thought to include problems with the sympathetic nervous system—the part of your nervous system that controls many automatic actions in your body such as sweat production, blood flow, and hair and nail growth^[6].

How CRPS is Diagnosed

There is no single test that can definitely diagnose CRPS^[9]. Diagnosis of CRPS is based on a physical exam and your medical history^[9]. CRPS is diagnosed clinically, which means a doctor makes the diagnosis based on your symptoms using standardized diagnostic criteria^[7].

Diagnosing CRPS can be difficult because it involves having tests to rule out other possible causes^[4]. Since the symptoms of CRPS usually improve over time, it is easiest for healthcare providers to diagnose it in the early stages. It is important to see a provider soon after you experience symptoms of CRPS^[3].

Tests are not necessary for the diagnosis of CRPS, but they can be useful to rule out other conditions^[7]. Some procedures that may provide important clues include^[9]:

• Bone scan—this procedure might help find bone changes. A radioactive substance is injected into one of your veins, which allows your bones to be seen with a special camera
• Sweat production tests—some tests can measure the amount of sweat on both limbs. Uneven results may indicate CRPS
• X-rays—loss of minerals from your bones may show up on an X-ray in later stages of the disease
• Magnetic resonance imaging (MRI)—images captured with an MRI test may show tissue changes that rule out other conditions

It is best to get help as soon as possible, as early treatment may help reduce your painful symptoms^[4]. The longer a person has CRPS without getting treatment, the more difficult it is to treat^[5].

Treatment Options

There is currently no cure for CRPS^[4][10]. Treatment is most effective when started early. In such cases, improvement and even complete recovery are possible^[1]. Early aggressive treatment may lead to prevention of chronic, disabling pain^[7][13].

There is no single proven treatment for CRPS, and there have been no large studies comparing different CRPS treatments^[7]. Most treatments are based on studies of their use for other types of nerve pain^[7].

The main goal of treatment is to improve function of the affected body part and to decrease pain^[7]. Treatment requires multiple approaches, including medications, physical therapy, and psychological support^[7]. Often, a combination of different treatments, tailored to your specific case, is necessary^[9].

Treatment for CRPS involves four main areas^[10][4]:

• Education and self-management
• Physical rehabilitation
• Pain relief
• Psychological support

Education and Self-Management

As part of your treatment, you will be advised about things you can do yourself to help control your condition^[10]. This may include:

• Education to help you understand your condition
• Support to stay active and use the affected body part
• Learning techniques to help you manage increases in pain
• Learning relaxation methods to help improve your quality of life
• Advice on activity management to help avoid dips in activity despite pain
• Continuing rehabilitation treatments at home, such as techniques to reduce sensitivity
• Accessing any support groups in your local area^[10]

It is important to understand that the painful limb is not damaged, so it does not need to be rested to heal. Recognizing this is key to overcoming the stress, anxiety, fear, anger, and depression that often come with CRPS^[16].

Physical Rehabilitation

Physical rehabilitation involves a number of different treatments. The aim is to gradually allow you to increase your activities and function without making the pain worse^[10]. This can be difficult because any movements or touch of the limb may increase pain or other symptoms of CRPS, such as swelling and color changes^[10].

Too much or too vigorous exercise can make the condition worse, so it is important for your therapy to be supported by a therapist with experience in CRPS^[10].

Your exercise plan may include a range of gentle exercises, from simple stretches to exercises in water or weight-bearing exercises^[10].

Desensitization is a technique used to reduce the sensitivity of body parts affected by CRPS. It usually involves touching an unaffected body part close to the affected area with materials of different textures, such as wool and silk, and focusing on how this feels. The same materials are then gradually applied to the painful affected body part while you try to recall what it felt like when they were touching the unaffected area. This process is likely to be uncomfortable or painful at first, but it may eventually reduce the sensitivity in the affected body part^[10].

Mirror visual feedback and graded motor imagery are techniques that aim to improve movements by retraining the brain. With CRPS, movement can often be difficult because information the brain needs to perform movements is often missing or confused^[10].

Pain Relief

There are several medicines that may help treat CRPS. Your treatment team will try lower-strength painkillers first and will only use stronger painkillers if necessary^[10].

Pain relievers: Pain relievers available without a prescription, such as aspirin, ibuprofen, and naproxen sodium, may ease mild pain and inflammation. Your doctor may prescribe stronger pain relievers if over-the-counter ones are not helpful. Prescription pain medications might be an option, but they should be taken in low doses^[9].

Antidepressants and anticonvulsants: Sometimes antidepressants, such as amitriptyline, and drugs usually used to treat seizures, such as gabapentin, are used to treat pain that comes from damaged nerves^[9].

Corticosteroids: Steroid medications, such as prednisone, may reduce inflammation and improve movement in the affected limb. Evidence suggests that a short course of oral corticosteroids can significantly improve pain in patients with CRPS^[7][13][9].

Bisphosphonates: These are medications that help prevent bone loss. During recent years, bisphosphonates have been the most studied drugs in CRPS treatment, and there is good evidence to support their use in this condition. Evidence suggests that bisphosphonates significantly improve pain in patients with CRPS^[7][13][12].

Advanced Treatment Options

Patients with persistent symptoms that affect their quality of life despite treatment with medications, counseling, and physical therapy should be referred to a pain management specialist to discuss additional treatment options^[7][13].

Spinal cord stimulation: This treatment works by creating sensations in the painful area that block pain signals. It can also help normalize spinal cord and brain signaling. For some patients, spinal cord stimulation is an option^[5][9].

Other advanced options may include nerve blocks, intrathecal drug pumps (where medication is delivered directly to the spinal fluid), ketamine infusions, peripheral nerve stimulators, and sympathetic ganglion blocks^[7][13].

Psychological Support

Chronic pain often leads to emotional exhaustion. CRPS can cause psychological side effects such as anxiety, hopelessness, or loneliness, particularly if pain does not improve with treatment^[21]. Living with CRPS can affect your mental health and that of your family or caregivers. You might find that you or your caretakers or loved ones experience depression, anxiety, or even post-traumatic stress. All of these conditions can worsen your perception of pain, which can impact your recovery and daily functioning^[20].

Together with physical therapy, psychological therapy is often prescribed to teach coping skills, including how to replace negative thoughts with positive ones^[16]. Cognitive behavioral therapy and mindfulness techniques can help you cope with the emotional impact of living with CRPS^[10][4].

What to Expect

CRPS can be either acute (short-term) or chronic (lasting longer than six months)^[3]. Whether a person has a mild or severe case of CRPS depends not only on the severity of the original injury but also on the person’s underlying health^[2].

Early studies suggested that most CRPS patients recover and very few have pain after one year. More recent studies have found that while pain symptoms and disability improve with time, most people have some degree of pain after one year^[2].

It is estimated that around 85 percent of people with CRPS slowly experience a reduction in their pain and some of their symptoms in the first two years^[10][19]. But some people experience continuous pain despite treatment^[10].

Severe or long-lasting cases of CRPS are very disabling and can prevent a person from working or doing their usual activities^[2]. In rare cases, further problems may develop, such as muscle wasting in the affected limb^[10]. There is currently no way to predict who will improve and when this may happen^[10].

Although most cases of CRPS resolve on their own without treatment^[7][13], the pain, associated symptoms, psychological impact, and disability require a well-informed, patient-centered approach^[7].

Living with CRPS

Living with CRPS reshapes daily routines, physical abilities, and emotional well-being^[21]. Each day with CRPS presents unique challenges, but the right knowledge and routines can significantly improve quality of life^[21].

Staying Active

Contrary to what might seem natural, rest alone worsens CRPS. Physical inactivity can cause muscle wasting, stiffness, and more pain^[21]. With guidance, gentle movement helps restore movement ability. Even 10 minutes of functional movement daily improves outcomes over time^[21].

Staying active delivers key physical and mental benefits when dealing with CRPS. Whether through physical therapy or a practice like yoga, staying active gets your blood flowing to combat inflammation, encourage nerve growth, deliver healing resources, and maintain strength and flexibility in your affected limb^[23].

Managing Pain at Home

Managing CRPS pain requires both active and responsive methods. Since pain intensity varies, people must adapt to their daily pain level and identify personalized coping tools^[21].

Daily management techniques include^[5][21]:

• Hot or cold packs for symptom relief
• Pacing and resting between tasks to reduce flare-up risk
• Tracking triggers to understand what makes pain worse
• Gradual desensitization exercises

Nutrition and Inflammation

What you eat influences how your body responds to pain. A diet focused on reducing body-wide inflammation supports nervous system health and may decrease the intensity of flare-ups^[21]. Eating foods with omega-3s, turmeric, ginger, dark leafy greens, legumes, and whole grains can help. Staying well-hydrated is equally important, and reducing sugar intake may help because it can contribute to inflammation^[21].

Mental Health and Coping

Deep breathing exercises are great for managing pain, as they soothe your nervous system. A good exercise to start with is 4-4-4-4 breathing: breathe in for 4 seconds, hold for 4 seconds, breathe out for 4 seconds, hold for 4 seconds^[23].

Finding ways to soothe and distract your brain can help. For example, you might try mindfulness techniques like meditation. Or perhaps you can try distraction—keeping your mind focused on a new activity, such as a game or hobby^[23].

Starting a gratitude journal can also help. Write down five things you are grateful for each night^[18].

Seeking Support

It can be difficult to always have to put on a brave face for loved ones around you, so finding support in CRPS support groups is recommended. The participants understand what you are going through and can offer not only support but practical advice^[23].

Have someone to talk to. It is helpful to have a professional who knows about chronic pain to help you cope^[18].

Practical Tips

Do not be afraid of anything that can assist you. Get a handicap parking permit if it means you will go out more and participate in daily life now that you do not have to walk so far^[18].

Be upfront when you need medical care. If you go to an emergency room, bring your medical records, pictures of your CRPS, and information about your condition. Always keep emergency guidelines for CRPS patients printed out and stored safely at home^[18].

Try to live as normally as you can. Your mindset is important when living with CRPS^[18].