Carpal tunnel syndrome has become a common scapegoat for all wrist-related pain, but it usually isn’t the actual culprit.

Carpal tunnel syndrome is arguably the most famous orthopedic condition of the modern age. The condition is actually a compressed nerve and has little or nothing to do with the wrist or carpal bones. Although carpal tunnel syndrome affects 3 percent of Americans — more than 8 million people — it is more common for doctors to see patients who are referred with this diagnosis but really have something else.

True carpal tunnel syndrome is a compression of the median nerve, the nerve that passes through the carpal tunnel on its way to the fingers and thumb.

If you look at your own hand with the palm up, the floor of this carpal tunnel is made up of the bones of your wrist. The roof of the tunnel is a strap of ligament (carpal ligament) that spans the distance from the base of the thumb to the base of the small finger side of the palm. Through this canal run all the tendons that bend your fingers and this one darn nerve. The problem here is not the nerve; it’s the company it keeps. When positioned at the extremes of flexion or extension, or placed in any sustained posture for a prolonged period of time, the tendons take up most of the available space in the canal, and the nerve gets crowded or pinched. The symptoms of carpal tunnel syndrome are nerve symptoms in the areas where the median nerve goes. This means numbness or tingling in the thumb and index, middle, and part of the ring fingers and sometimes weakness in the thumb muscles. Patients typically will describe this as the “hand going to sleep,” and because this occurs frequently at night, people rarely realize the little finger is not affected. “My whole hand goes to sleep, Doc,” is a common symptom. This uncomfortable feeling might be associated with pain, burning, or feeling a loss of circulation, but the primary feature of carpal tunnel syndrome should always be numbness.

To cloud the issue even more, there can be associated pains anywhere along the path of the median nerve on its way from the neck to the hand. Shoulder pain is common, as is forearm and even neck pain. So, you can see that this common problem might have some uncommon symptoms, which makes it confusing to get to the bottom of a diagnosis. Often the doctor will order nerve conduction studies to test the way the median nerve conducts electricity along its route. If the problem truly is carpal tunnel syndrome, there usually will be a slowing of conduction across the wrist.

Once a diagnosis of carpal tunnel syndrome is confirmed, there are four options for treatment, which often are used in combination:

• avoiding the activities that provoke it;
• splinting, particularly at night;
• cortisone shots to shrink swelling in those pesky neighboring tendons; and
• surgery to raise the roof of the tunnel and make more room for the nerve.

You can look into workplace modifications, pressure from keyboards, wrist pads, and all that, but ultimately, we were not designed to sit at a keyboard and hammer away for eight hours a day.

Because I see many patients with this condition, carpal tunnel release is one of the most common procedures I perform. We usually start with rest, splinting, and injections, but in cases where there already is a wasting of the thumb muscles where the nerve enters, constant numbness that doesn’t go away during the day, or waking up seven out of seven nights with symptoms despite splinting, it’s necessary to skip straight to surgery.

Patients often ask if they are risking permanent nerve damage by putting off surgery. If they wait until they have numbness all day long or weakness in the thumb muscles supplied by the median nerve, then yes. Otherwise it’s safe to wait and continue with splinting and injections — as long as they are helpful.

The surgery leaves a small scar in the palm, which is tender for several weeks but usually fades to almost nothing within the first year. I’ve had patients who have had surgery on one hand done years ago, and neither they nor I can tell which one it was by looking at the palm. Complications include stiffness requiring physical therapy, injury to the nerve at surgery, pain in the palmar scar, and recurrence. That’s right: You can have an excellent surgical result and recreate the problem by going back to the same work habits or just by further compression of the nerve over time. Surgery is much less amenable for those unfortunate patients who find themselves in this situation. Then it’s definitely time to go job hunting.

About the author: Dr. Michael R. Wilson, M.D., is an orthopedic surgeon who received training at the Mayo Clinic. He is the author of The Other Midlife Crisis: Arthritis and all Those Aches and Pains.