If you’re reading this at work, you are probably worried that something you’re doing right now is slowly killing you. The accumulated years of slouched spinal posture, squinting at a screen, and sitting (“the new smoking”) are sources of health paranoia for the 80 percent of the workforce whose jobs do not regularly require physical activity.

And then there’s typing.

The anxiety over long sedentary workdays is often crystallized in fears of carpal tunnel syndrome (CTS), a wrist ailment that is so associated with repetitive hand activities that the image attached to the Google medical information profile for it is an intently focused woman in an open-office plan sitting at a desk with one hand on a mouse and the other typing.

However, capitalism is probably off the hook for CTS: There is scarce data that excessive keyboard work causes carpal tunnel syndrome.

What carpal tunnel syndrome is

CTS is a condition in which the carpal tunnel—the part of the wrist containing the median nerve that runs from the forearm into the palm—becomes pressed or squeezed, causing burning, tingling, numbness, and/or stiffness.

The cause is often due to inflammation. Sprains, fractures, and injuries to the wrist can instigate CTS. Metabolic factors, like an overactive pituitary gland or an underactive thyroid gland, can also induce that kind of bodily reaction. Fluid retention during pregnancy or menopause is also a possible culprit, and this is one reason women are three times more likely to experience CTS than men.

Onset typically occurs sometime between ages 30 and 60.

While wrist injuries can start a bodily reaction leading to CTS, clicking and typing themselves don’t put much stress on the carpal tunnel.

Numbness, not pain, is the surest sign of carpal tunnel syndrome

Alejandro Badia, MD, co-founder and chief medical officer of the Badia Hand to Shoulder Center near Miami, says he often sees patients with wrist pain who are sure their 9-to-5 is the source. “I have patients come in so hell-bent on what’s causing it,” he said.

Misconceptions about computer posture cause patients to mistake pain around the wrist for CTS, Badia said. “But the tell-tale sign [of carpal tunnel syndrome] isn’t pain; it’s numbness.”

Pain and shock-like sensations are not unheard of in CTS cases, but numbness, tingling, and burning are more common effects of the carpal tunnel nerve misfiring and struggling under pressure. These feelings often come when the patient is trying to sleep, a time when wrists are often bent.

Many of Badia’s patients who think they have CTS actually have tendonitis, a painful repetitive stress injury caused by overuse of the tendons in the same ligaments, including ones in the wrist. Overuse causes inflammation or irritation of a tendon, which connects the muscle to bone. Depending on the area affected, tendonitis has a variety of nicknames, including “tennis elbow” and “swimmer’s shoulder.”

The treatments are drastically different. An injury to the tendon may require a combination of rest and physical therapy. Carpal tunnel syndrome requires a different approach, so see a medical professional to figure out what the problem really is.

What to do if you think you have carpal tunnel syndrome

If you feel numbness and tingling and think you have CTS, “the first thing to do is call a doctor,” said Christopher Stevens, an orthopedic surgeon who specializes in upper extremities at the Tucson Orthopaedic Institute. There is a vast range of courses of actions one should take depending on the severity of the problem, and a professional can guide you through them.

Your best treatment could be a specialized splint that takes pressure off the carpal tunnel. For mild cases, wearing such a splint puts the nerve back in working order after a few weeks. More extreme cases may require anti-inflammatory medication or hand surgery. Severe CTS can cause one to lose control over one’s hands.

Who actually gets carpal tunnel syndrome?

There isn’t much you can do to prevent carpal tunnel syndrome. Biological and metabolic factors rule the categories of known causes.

The research that explores the role of hand overuse actually shows that people in blue-collar jobs are somewhat more likely to suffer than those tied up in a cubicle all day. A British study found that packers, assembly line and food processing laborers, and workers who used vibratory power tools were the most likely types of employees to have CTS, not data entry professionals or administrative assistants. They put the greater strain on their hands and risk injury.

Still, with being female increasing one’s chances of getting CTS threefold, biology is a greater factor than lifestyle for the ailment.

The gender ratio of CTS offers a historic reason why carpal tunnel came to be misunderstood as a white-collar ailment. “If you think of the population who first showed up with signs of carpal tunnel syndrome, it was middle-to-late-age females,” said Stevens.

In the mid-20th century, when carpal tunnel syndrome was first widely recognized and diagnosed, women had been shoehorned into secretarial work. So began the misconception that typing and repetitive hand tasks cause CTS.

Actually, it was probably pregnancy or menopause that was causing inflammation and fluid retention that put pressure on these women’s carpal tunnel nerves. “I think it’s one of those myths that has never really been dispelled,” said Stevens.

Some states’ and countries’ worker compensation laws still mistakenly associate typing with CTS or use vague language, said Stevens, causing greater confusion.

Also, for someone lifelessly twiddling their life away at some Dunder-Mifflin-like company, there is a psychological magnetism to the notion their job is causing them literal pain. “That’s part of it,” said Stevens. “If your work is unsatisfying, you are going to attribute ailments to it.”

So your job may be killing you, but only on the inside.