Believe it or not, carpal tunnel syndrome is yet another “complication” associated with diabetes.

Beyond simple forearm discomfort, it can be quite debilitating. Here’s an overview for people with diabetes on what carpal tunnel syndrome is exactly, and what you can do about it.

As you probably know, carpal tunnel syndrome (CTS) is a progressively painful hand and arm condition that develops from a pinched nerve in your wrist.

It specifically affects the median nerve, which runs through the carpal tunnel from your hand into your forearm. The median nerve provides feeling to the palm side of your fingers, and is the muscle power that powers your thumb.

When the median nerve is pinched from swelling of nerves or tendons in the carpal tunnel, numbness, tingling, and pain can affect the hand and fingers. It can also lead to other symptoms, like poor circulation and loss of grip strength.

The root cause of the condition is unknown. But with diabetes, researchers believe that high blood glucose levels make the tendons of the carpal tunnel become glycosylated. That means the tendons become inflamed, and excess sugars form a “biological superglue” that makes the tendons less able to slide freely — similar to what happens in frozen shoulder.

In the general population, CTS affects between 2 and 3 percent of people, but it seems to cluster around people who are already dealing with other health challenges.

The most common conditions linked to carpal tunnel syndrome are:

  • diabetes (that’s us)
  • thyroid conditions (that’s most of us, as diabetes and thyroid conditions are bosom buddies)
  • high blood pressure (again, common among people with diabetes)
  • autoimmune disorders (applies to those of us with type 1 diabetes)

Research shows that CTS appears in up to 20 percent of people with diabetes, “suggesting that the link between diabetes and carpal tunnel syndrome could be due to excessively high blood sugar levels.”

In fact, some years ago research evidence was being circulated that CTS might actually predict type 2 diabetes.

In 2014, Dutch researcher Steven H. Hendriks and his team decided to look at the issue afresh and attempt to weed out confounding factors — other conditions that confuse data sets in clinical research.

What they found was that while type 2 diabetes was more frequently diagnosed in people with CTS, it couldn’t be singled out as an independent risk factor after they adjusted for body mass index, gender, and age.

In other words, the type 2 population shares the demographic of the CTS population. And, tellingly, they found no association between CTS and the duration of diabetes, the level of glycemic control, or the degree of microvascular complications — all of which you’d expect if diabetes and CTS had a direct relationship.

So, it just may be that more weight, older age, and being female increases the risk of both diabetes and CTS.

Regarding type 1 diabetes, one seminal study — albeit 15 years old — showed a “lifetime risk of symptomatic carpal tunnel syndrome in people with T1D.” Oy!

In a rare case of diabetes being good news for a change, while we have more CTS than other folks, we don’t tend to get its most severe form. That dubious honor goes to people with metabolic syndrome (which can exist either with diabetes or independently of it).

Add the fact that folks who spend a lot of time typing on computers have an occupational risk factor (and of course you know we type 1s are an internet-savvy set!).

We found it interesting that in addition to the “keyboarding occupations,” other occupations with a high-risk for CTS include:

  • assembly line workers who use repetitive wrist motions
  • construction workers who use vibrating power tools
  • professional musicians

Lots of folks may wonder whether they got CTS or have a higher risk for it if someone else in their family has it. The answer is yes: Genetics are at play here.

Medical experts say there’s definitely a genetic component to CTS, which is especially the case when it hits young people.

Other genetic factors that may contribute to developing CTS include abnormalities in certain genes that regulate myelin, a fatty substance that insulates nerve fibers.

Basically, just like with diabetes, if you have a family history of the condition, you’re more likely to get it.

CTS is actually part of the neuropathy family. It’s sometimes called an “entrapment neuropathy.” To better understand how a nerve can become entrapped, it helps to visualize how the carpal tunnel is built.

The carpal tunnel is a narrow passageway in your wrist between your forearm and hand. And just like some terrestrial tunnels are shared by both roads and rails, the carpal tunnel in your body is shared by both tendons and nerves.

In some people, “traffic congestion” in the carpal tunnel can lead to fender benders that affect the primary nerve to the hand, causing CTS.

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Image via American Academy of Orthopedic Surgeons

If you were to cut your hand off — not that we’re recommending it — and flop it on the table palm up, you’d find that the carpal tunnel is more like a covered aqueduct than a proper tunnel.

It’s a U-shaped trough of small bones. At the base of the trough are the flexor tendons that power your fingers. Along the top of the bundle of tendons runs the median nerve, the pipeline for sensation for the thumb, index finger, middle finger, and part of the ring finger.

Over the top of the channel runs a band-like strap of ligament called the transverse carpal ligament. It could be described as a small trench with a lot of plumbing running through it.

CTS happens when the tendons at the base of that trench get inflamed. As they swell, they press upward on the nerve, and the nerve gets pinched (entrapped) between the swelling tendons at the bottom of the shaft and the ligament strap at the top.

And squished nerves transmit pain signals.

Symptoms range from numbness or tingling on the thumb-side of the hand to horrible, crippling pain. The pain can be felt in the hands, wrist, or forearm. It usually strikes the dominant hand first, but in about half of people who have CTS, it’s bilateral, causing pain on both sides of the body.

In case you think it’s just a case of sore wrists, think again. The pain can be surprisingly intense! Our own DiabetesMine editor-in-chief, Amy Tenderich, has dealt with CTS, writing in 2008:

“I never imagined how painful or debilitating it can be. At its worst, I could literally not make toast for my kids in the morning, let alone help them button their sweaters. I could barely hold my blow-dryer up straight, and was wiped out from being up all night with the pain.”

At one time, it was believed that repetitive motion of the wrists actually caused CTS. Now most experts agree that isn’t the case.

Rather, there’s consensus that CTS is exclusively caused by the size of the carpal tunnel and is exacerbated by repetitive motion. (This is in much the same way that obesity doesn’t cause diabetes if you’re not predisposed, but can trigger it if you are.)

Just as tunnels through mountains vary in length and bore, so too, apparently, do carpal tunnels in people, creating a congenital predisposition.

Sorry, gang, size really does matter. At least for CTS.

Basically, people with smaller tunnels are more likely to get CTS, largely due to the fact that the margin for error is so small: It doesn’t take much swelling to pinch off a smaller tunnel.

This also might explain why women are three times more likely to get CTS than men. They have smaller wrists, and hence smaller carpal tunnels.

Maybe this means that if you have a small tunnel, work on the assembly line during the day, and play in an amateur piano league at night, you’re really in for it.

Meanwhile, as to the connection between diabetes and CTS, who knows? Maybe the genes that cause diabetes also cause small carpal tunnels.

Keep in mind that symptoms for carpal tunnel start gradually, so it’s important to see your doctor early if you’re often feeling “pins and needles,” or a burning or loss of sensation in your hands.

Do you wake up at night with your hands or thumbs feeling numb, like they’ve “gone to sleep”?

When you do get examined, your doctor will run some tests, most importantly to make sure that you don’t have peripheral neuropathy. The two conditions can feel similar but aren’t the same thing. They require different treatments.

Two clinical tests used to diagnose CTS are the Tinel and Phalen maneuvers, which sound really scary but are actually just flexing exercises to check if you experience a tingling sensation in your hands or wrists.

In the Tinel’s sign test, your doctor taps the inside of your wrist over the median nerve. If you feel tingling, numbness, or a mild “shock” sensation in your hand, you may have CTS.

The Phalen test has you resting your elbows on a table, and then letting your wrists dangle so your hands are pointing down with your palms pressed together in the prayer position. (This video sums it up nicely.) A positive result is when your fingers tingle or feel numb within a minute.

Treatments for CTS range from rest and wrist splints to medications, physical therapy, and even surgery.

For most folks, avoiding activities that aggravate the wrist (which, sadly, includes working on the computer), wearing a hand splint, and taking ibuprofen can help with the pain and keep the pressure off the median nerve until things heal.

Other home remedies you can try include stretches and elevating your hands and wrists whenever possible.

Ice or heat for CTS?

While keeping your hands warm can help with pain and stiffness, medical experts recommend icing joints that are known to be affected CTS.

A 2015 study concludes that “application of cold to the hand may reduce compression of the carpal ligament and nerve.”

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Your doctor may recommend corticosteroids to lessen your pain and inflammation. These drugs reduce the amount of swelling and pressure placed on the median nerve.

Injections are more effective than oral steroids. This therapy may be particularly effective if an inflammatory condition is causing your CTS, such as rheumatoid arthritis.

If your condition doesn’t improve within a few months, your doctor may recommended that you see an orthopedic surgeon or neurologist to talk about surgery.

In fact, CTS surgery is one of the most common surgeries performed in the United States.

Remember that carpal ligament we talked about at the start? The “roof” of the carpal tunnel? In the traditional CTS open release surgery, the ligament is cut to relieve pressure.

Basically, the tunnel is routed out to create a larger bore. Any other tissue (such as a tumor) that may be putting pressure on the median nerve can also be removed during surgery.

There are actually two methods of carpal tunnel surgery, called open and endoscopic. But be aware: Neither is foolproof.

According to experts, both are 95 percent effective. Nevertheless, each has advantages and disadvantages, mostly related to ongoing discomfort after the surgery.

The less invasive endoscopic version requires a much smaller incision, which reduces pain, recovery time, and scarring. But according to this helpful video from the Hand and Wrist Institute, in about 2 percent of cases, physicians can’t see the tissue properly to do the endoscopic surgery safely, so they have to resort to the “open” version.

Naturally, diabetes also complicates things. Many medical sources still state the disclaimer: “Surgery may only provide partial relief when another medical condition, such as rheumatoid arthritis, obesity, or diabetes, is contributing to carpal tunnel syndrome.”

Scott King, a type 1 and former editor of Diabetes Health magazine, had CTS for a long time. He finally made the move to have general arthroscopic wrist surgery several years ago. After the procedure, he shared with us:

“I have only one little hole in both wrists, almost healed now but scars are still sensitive and I can TYPE again with no pain! The worst part after the surgery was that my hands hurt horribly for the first 2 days… but a week later I was flying out on a business trip, and everything was great! I do wish I had the surgery earlier, as I still have tingling in my left hand from permanent damage to the nerve.”

Clearly, choosing whether to undergo surgery is a big decision. Check out this guide from Ortho Illinois to help you make a decision.

So, what else can you do to prevent CTS?

In addition to keeping blood sugars in range (best way to prevent ALL complications!), a good way to offset CTS risk is keeping your wrists straight as much as possible and avoid flexing them unnecessarily — which often happens when we sit in front of our ubiquitous computers for too long.

To help with this, DiabetesMine’s Amy Tenderich even had a certified ergonomics specialist visit her home office at one point to check the setup of her chair height and keyboard. Sounds pretentious, but it actually really helped, she says.

Experts agree that ergonomic positioning can help prevent pinching the nerves in your wrist and is super helpful for both prevention and treatment of CTS.

Also, there are some simple wrist stretch exercises you can do at your desk anytime to help prevent CTS and keep your hands and arms healthy and loose.

So, any people with diabetes out there dealing with CTS? We really feel for you!


Wil Dubois lives with type 1 diabetes and is the author of five books on the illness, including “Taming The Tiger” and “Beyond Fingersticks.” He spent many years helping treat patients at a rural medical center in New Mexico. An aviation enthusiast, Wil lives in Las Vegas, NM, with his wife and son, and one too many cats.