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Carpal Tunnel Syndrome

Medically Reviewed by Dan Brennan, MD on January 19, 2023

What Is Carpal Tunnel Syndrome?

Carpal tunnel syndrome, also called median nerve compression, is a condition that causes numbness, tingling, or weakness in your hand.

It happens because of pressure on your median nerve, which runs the length of your arm, goes through a passage in your wrist called the carpal tunnel, and ends in your hand. The median controls the movement and feeling of your thumb and the movement of all your fingers except your pinky.

Carpal Tunnel Symptoms

Symptoms of carpal tunnel include:

  • Burning, tingling, or itching numbness in your palm and thumb or your index and middle fingers
  • Weakness in your hand and trouble holding things
  • Shock-like feelings that move into your fingers
  • Tingling that moves up into your arm

You might first notice that your fingers "fall asleep" and become numb at night. It usually happens because of how you hold your hand while you sleep.

In the morning, you may wake up with numbness and tingling in your hands that may run all the way to your shoulder. During the day, your symptoms might flare up while you’re holding something with your wrist bent, like when you’re driving or reading a book.

Early on in the condition, shaking out your hands might help you feel better. But after some time, it may not make the numbness go away.

As carpal tunnel syndrome gets worse, you may have less grip strength because the muscles in your hand shrink. You’ll also have more pain and muscle cramping.

Your median nerve can’t work the way it should because of the irritation or pressure around it. This leads to:

  • Slower nerve impulses
  • Less feeling in your fingers
  • Less strength and coordination, especially the ability to use your thumb to pinch

 

Carpal Tunnel Syndrome Causes

Often, people don't know what brought on their carpal tunnel syndrome. It can be due to repetitive motions, like typing, or any wrist movements that you do over and over. This is especially true of things you do when your hands are lower than your wrists. This is especially true of things you do when your hands are lower than your wrists.

Carpal Tunnel Syndrome Risk Factors

You might have a higher risk of getting carpal tunnel syndrome if you:

  • Are a woman. Women are three times more likely than men to get it. This might be because they tend to have smaller carpal tunnels.
  • Have a family member with small carpal tunnels
  • Have a job in which you make the same motions with your arm, hand, or wrist over and over, such as an assembly line worker, sewer or knitter, baker, cashier, hairstylist, or musician
  • Fracture or dislocate your wrist

 

Carpal Tunnel Syndrome Diagnosis and Tests

Your doctor may tap the palm side of your wrist, a test called Tinel sign, or fully flex your wrist with your arms extended. They might also do tests including:

  • Imaging tests. X-rays, ultrasounds, or MRI exams can let your doctor look at your bones and tissues.
  • Electromyogram. Your doctor puts a thin electrode into a muscle to measure its electrical activity.
  • Nerve conduction studies. Your doctor tapes electrodes to your skin to measure the signals in the nerves of your hand and arm.

 

Carpal Tunnel Syndrome Treatment

Your treatment will depend on your symptoms and how far your condition has progressed. You might need:

  • Lifestyle changes. If repetitive motion is causing your symptoms, take breaks more often or do a bit less of the activity that’s causing you pain.
  • Exercises. Stretching or strengthening moves can make you feel better. Nerve gliding exercises can help the nerve move better within your carpal tunnel.
  • Immobilization. Your doctor may tell you to wear a splint to keep your wrist from moving and to lessen pressure on your nerves. You may wear one at night to help get rid of that numbness or tingling feeling. This can help you sleep better and rest your median nerve.
  • Medication. Your doctor may give you anti-inflammatory drugs or steroid shots to curb swelling.
  • Surgery. If none of those treatments works, you might have an operation called carpal tunnel release that increases the size of the tunnel and eases the pressure on your nerve.

 

Carpal Tunnel Syndrome Complications

If you have carpal tunnel syndrome and don't treat it, the symptoms can last a long time and get worse. They could also go away and then come back. When you get a diagnosis early, the condition is easier to treat. You can avoid permanent muscle damage and keep your hand working the way it should.

To avoid carpal tunnel syndrome, try to:

  • Keep your wrists straight.
  • Use a splint or brace that helps keep your wrist in a neutral position.
  • Avoid flexing and extending your wrists over and over again.
  • Keep your hands warm.
  • Take breaks whenever you can.
  • Put your hands and wrists in the right position while you work.

 

How Do I Know if I Have Carpal Tunnel Syndrome?

Your doctor may use a handful of tests to diagnose carpal tunnel syndrome and rule out other causes of hand and wrist pain.

They’ll probably start with questions about your medical history. Then they’ll examine your hands, arms, shoulders, and neck to figure out if your pain results from another condition, like an injury or arthritis. They’ll also make sure your daily activities aren’t to blame.

The doctor may focus on your wrist to see if the area is tender, swollen, warm, or discolored. They’ll probably test each finger to see if you’ve lost any feeling. And they’ll check the strength of the muscles in your hand.

After that, they may do tests focusing on the median nerve, which runs through your forearm into your hand. When that nerve gets pressed or squeezed through the carpal tunnel, it causes carpal tunnel syndrome.

Carpal Tunnel Syndrome Tests

Tinel’s Sign

The doctor will tap or press on the median nerve in your wrist with a reflex hammer. If your fingers tingle or if you feel an electric-shock-like sensation, the test is positive. You may have carpal tunnel syndrome.

Phalen’s Maneuver

This is also known as the wrist-flexion test. The doctor will tell you to press the backs of your hands and fingers together with your wrists flexed and your fingers pointed down. You’ll stay that way for a minute or two. If your fingers tingle or get numb, you have carpal tunnel syndrome.

Two-Point Discrimination Test

This means you can tell if two objects touching your skin are two distinct points instead of just one. The doctor may use a gadget called a 2-point disk-criminator, a small, flat, eight-sided tool with needle-like prongs sticking out from all sides.

They might do the test several times on each finger. They’ll start with two points touching your skin a few centimeters apart and move them closer together until you feel just one point of pressure.

The distance at which you can feel only one point will help them figure out nerve function and compression – two important components of carpal tunnel syndrome.

Nerve Conduction Velocity Test

This test provides some of the strongest evidence of carpal tunnel syndrome. It measures how fast an electrical signal can travel along a nerve or from the nerve to a muscle.

The doctor places a small electrode on your skin near your elbow. It sends a mild electrical current down your median nerve. The more time it takes for the current to travel from your elbow to your fingers, the more damage to your median nerve.

Electromyogram

This works like the second part of the nerve conduction velocity test. It measures how well the muscle around your median nerve works. The doctor places a small needle electrode into muscles in your hand and arm that get impulses from the median nerve. The needle sends electric impulses into the muscle. You relax and flex your hand several times. The doctor can tell if your median nerve is damaged or being squeezed.

The needles might hurt a little, but it should stop once the doctor takes them out. You may feel twitches or spasms from the electrical current. You could have some bruising where the electrode went in, but that should go away within a few days.

Ultrasound, X-ray, and MRI

Your doctor may order one of these tests to rule out other causes of wrist and hand pain. An X-ray can show arthritis or a broken bone. An ultrasound or MRI will show a swollen or compressed median nerve. They’ll also tell the doctor why it is being squeezed, whether it’s arthritis, carpal tunnel syndrome, or another reason.

They might also order lab tests, like bloodwork, to look for diseases like diabetes that can damage your nerves.

Other Physical Examination

Your doctor will also ask you about any patterns with your symptoms. For example, if you have tingling or numbness in your little finger, it may not be carpal tunnel syndrome since the median nerve doesn’t provide feeling to that finger. The doctor may also ask if you have a history of symptoms:

  • While holding your phone or a newspaper
  • At night
  • In the morning

These are all signs of carpal tunnel.

Show Sources

SOURCES:

American Academy of Orthopaedic Surgeons: “Carpal Tunnel Syndrome.”

National Institute of Neurological Disorders and Stroke.

Mayo Clinic Proceedings: “The Many Faces of Carpal Tunnel Syndrome.”

Cleveland Clinic: “Carpal Tunnel Syndrome.”

Mayo Clinic: “Carpal tunnel syndrome.”

Johns Hopkins Medicine: “Carpal Tunnel Syndrome.”

National Institutes of Health: “Carpal Tunnel Syndrome Fact Sheet.”

Washington University School of Medicine in St. Louis: “Peripheral Nerve Surgery: A Resources for Surgeons.”

American College of Rheumatology: “Carpal Tunnel Syndrome.”

Mayo Clinic: “Carpal tunnel syndrome: Diagnosis,” “Electromyography: What you can expect.”

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