Complex Regional Pain Syndrome

Medically Reviewed by Jabeen Begum, MD on January 30, 2024
8 min read

Complex regional pain syndrome (CRPS) is a term for ongoing, intense pain and inflammation after an injury or medical event, like surgery. Although it can affect any part of your body, it's most likely to happen in one of your hands. It's also common to get CRPS in an arm, leg, or foot.

Experts believe that CRPS usually happens because of damage to, or a glitch in, your nervous system. But there's a lot that isn't yet known about this condition, including the best way to treat it.

In the past, CRPS was called reflex sympathetic dystrophy, causalgia, shoulder-hand syndrome, or Sudeck's atrophy. You might also hear it called CRPS disorder.

In most cases, CRPS happens after an injury or surgery. It's believed to be triggered by tiny nerve cells that carry pain signals to your brain. If they get damaged and send too many signals, your immune system can overreact. That sets in motion CRPS symptoms such as intense pain, swelling, and redness in an area.

For instance, CRPS could be triggered by:

  • A broken bone. A fractured bone could press on nearby nerves, as could a too-tight cast.
  • Muscle strain. A very tight muscle could squeeze surrounding nerves.
  • Surgery. Surgical tools, stitches/sutures, and the position you're in during a procedure can accidentally cause a nerve injury.
  • Wounds, burns, and cuts. Even a minor injury can damage nerves in the area.

CRPS could also be triggered by health issues such as an infection, cancer, heart attack, or stroke, although it's not as common.

Many other factors also play a part in CRPS. You may be more likely to get it if you have:

  • Poor circulation
  • Diabetes, or other health conditions that impact your nerves
  • Autoimmune issues
  • Inflammatory disease
  • Family members with CRPS

More research needs to be done on CRPS. So far, existing data shows that it's three to four times more likely to affect people who are assigned female at birth (AFAB.) CRPS also appears to be most common in people aged 50-74

If CRPS happens after an injury, your pain may seem extreme compared to the injury itself. It can also spread. For instance, after hurting your finger, your entire arm may feel tender and swollen. In some cases, the pain could even spread to your opposite arm. This is what doctors call "mirror pain." 

Other symptoms of CRPS include:

  • A sensation of "burning" pain
  • Feeling "pins and needles," like the area has fallen asleep
  • Extreme sensitivity to touch
  • Swelling and stiffness in affected joints
  • Finding it hard to move the affected body part
  • Changes in nail and hair growth (such as rapid hair growth or no hair growth)
  • Skin temperature changes; your skin may feel warmer or cooler compared to the opposite limb
  • Skin color changes; your skin could become blotchy, pale, purple or red
  • Skin texture changes; your skin might look shiny and thin, or feel very dry and thickened
  • Extreme sweating
  • Trouble sleeping
  • Muscle spasms
  • Tremors

Feeling stressed can make CRPS symptoms worse.

Because the effects of CRPS can grow more serious with time, the sooner you become aware of it, the better.

There's no specific test for CRPS. Instead, your doctor will need to get more information and try to rule out some other conditions. After a physical exam and questions about your symptoms, the tests you could have include:

  • X-rays, to check for mineral loss in your bones, a sign that your CRPS has progressed
  • Bone scans, to look for changes in your bones and how your blood circulates
  • Imaging tests, to check the soft tissues in your body and look for injured nerves
  • A sweat production test, to measure how much the affected body part is sweating; if you have CRPS, it may sweat more than your opposite limb

CRPS diagnostic criteria

A CRPS diagnosis can be difficult to make early on if your symptoms are limited or mild. Your doctor will look for a higher-than-expected amount of pain after a recent injury or medical event, and at least three of the following symptoms:

  • Increased sensitivity to pain or touch
  • Changes to your skin temperature, texture, or color
  • Sweating or swelling
  • Decreased range of motion or changes in movement (like tremors) or changes to your skin, hair, or nails

Your symptoms will need to be confirmed in person by your doctor.

Because there's no cure for CRPS, the main goal of treatment is to relieve painful symptoms. This can be done in a few different ways.

CRPS medication

If your symptoms are mild, over-the-counter pain relievers such as acetaminophen or NSAIDs (nonsteroidal anti-inflammatory drugs) such as ibuprofen may be enough to treat them. In other cases, your doctor may prescribe stronger medicines.

The FDA hasn't approved specific CRPS drugs. But different types of other medications can be helpful. They include:

  • Pain relief gels, creams, sprays, and patches. These can help numb the nerves at the site of your pain.
  • Nerve pain medications.
  • Blood pressure medications.
  • Corticosteroids. These can reduce swelling and redness.
  • Antidepressants.
  • Osteoporosis medicines. A group of drugs called bisphosphonates can help slow changes inside your bones.
  • Anti-seizure drugs.
  • Botox shots. These can help relax tight, painful muscles.
  • Opioids. These drugs come with many risks so should only be prescribed in severe cases of CRPS.

Other treatments include:

  • Heat therapy. A heating pad may help relieve swelling and pain.
  • Physical therapy. An expert can guide you through gentle exercises that improve how well you move.
  • Spinal fluid drug pumps: Very low doses of pain-relieving medication can be delivered directly into your spinal fluid.
  • Spinal cord stimulation. Electrodes placed next to your spinal cord can help block feelings of pain.
  • Peripheral nerve stimulators. Tiny implants next to your injured nerves may help improve your pain and make you more comfortable.

New treatments for CRPS

  • Repetitive transcranial magnetic stimulation (rTMS): This procedure can reduce pain by changing electrical signals in your brain. It's noninvasive, meaning that no surgery is needed.
  • Alternative treatments: Acupuncture, chiropractic treatments, relaxation techniques, and therapy can also be helpful ways to improve your symptoms. You can also talk to your doctor about whether medical marijuana could help you.
  • Ketamine: If you're in extreme pain and nothing else has helped, your doctor may suggest ketamine, an FDA-approved anesthetic, which can be given to you through an IV. Limited studies show that it may help reduce pain. But ketamine comes with many risks, so make sure you discuss the pros and cons with your doctor.

Doctors are trying to understand more about what causes CRPS. That can help them find ways to prevent it as well as better treatments. Studies are currently taking a closer look into the roles your immune system and genes play. If you want to volunteer to take part in a clinical trial that's testing out a new CRPS treatment, talk to your doctor.

The earlier that CRPS is diagnosed and treatment is started, the better the chances that it will go away. That process can take a few months or a few years. Children and teenagers usually make a full recovery. For adults, following a healthy lifestyle can improve your chances.

As you work on getting better, these steps may help:

  • Keep moving. Regular exercise, even for a few minutes each day, will improve blood flow and help maintain function in the affected area. Physical therapy can help you start moving safely.
  • Get plenty of rest. Ask your doctor if you should elevate (raise) the CRPS-affected limb when you sleep to help get rid of excess fluids.
  • Look to your family and friends for support. Share info about CRPS with your loved ones so they can better understand what you're dealing with.
  • Manage other health conditions. Stay on top of treatments for other conditions, such as diabetes, that also affect your nerves and blood flow.
  • Ask your doctor about compression stockings and sleeves. Their snug fit can help relieve swelling.
  • Eat healthy foods. If you're not sure what to put on your plate, ask your doctor for ideas.
  • Quit smoking. It can interfere with the healing process.
  • Find a doctor you trust. Although there's a lot that still isn't known about CRPS, find a doctor who takes your symptoms seriously and is eager to find a treatment that helps you feel better.

CRPS life expectancy

CRPS isn't life-threatening, but it can affect your quality of life. The longer CRPS goes on, the more severe it can become. In some cases, it can spread to other parts of your body. In 10%-30% of people, CRPS comes back after it clears up.

Learning how to manage your pain and improve function in the affected body part are the main goals of CRPS treatment.

Long-term pain can take a toll on your mind and emotions. Being depressed or feeling anxious can make it harder to recover, so tell your doctor. Therapy, lifestyle changes, and medication may help.

Your doctor should also be able to connect you with other health professionals who can help. They might teach you relaxation or meditation techniques, for instance. And in support groups, you can draw from other people's strengths and share yours with them.

CRPS is a complex condition that's still being studied. It's important to realize that it's not "all in your head," but has to do with injured nerves. The sooner you can find ways to manage your pain, the better your chances of a full recovery.

What are the three stages of complex regional pain syndrome?

Once you're diagnosed with CRPS, your doctor will decide which stage you're in, based on your symptoms.

Stage I (acute CRPS)

Common symptoms include:

  • Burning pain
  • A painful reaction to touch
  • Swelling
  • Stiff joints
  • Warmth and skin color changes in the affected limb
  • Excess sweating
  • Faster than normal hair and nail growth

This stage lasts 3 months or less.

Stage II (dystrophic)

Signs of this phase include:

  • Pain that has spread to other areas
  • Increased pain when touched
  • Swelling that doesn't go away
  • Skin wrinkles and folds may look "filled in"
  • Cooler skin
  • Increased stiffness
  • Cracked or easily broken fingernails

The dystrophic stage can last 3-12 months.

Stage III (atrophic)

Common signs of this stage are:

  • Less pain
  • Less function of the limb
  • Shiny skin
  • Dryness
  • Symptoms may have spread to other areas

Stage III CRPS is diagnosed when you've had symptoms for over a year.

Is CRPS a permanent disability? 

CRPS is short-lived most of the time. But for a small group of people, it can be severe and become a chronic (ongoing) issue. If your CRPS symptoms are severe enough to prevent you from working for at least 12 months, you may qualify for disability benefits. You'll need to file a claim through the Social Security Administration. If you need help, ask a friend or family member. You can also reach out to a CRPS nonprofit group that can help connect you to resources.