What Causes Carpal Tunnel Syndrome?

Carpal Tunnel Syndrome (CTS) is the compression – and sometimes squashing – of the median nerve that passes through the wrist. Its symptoms can include numbness, tingling and pain in the thumbs, fingers and wrists, which can travel as far as to the arms and even to the shoulder. Modern medicine has a firm grip on what CTS is; what causes it is quite a different story.

Diagnosing CTS can be done through a relatively simple physical examination. One test is called the ‘flick signal’, for which the patient is asked, ‘what do you do when your symptoms are worse?’ If the patient responds with a hand movement that resembles the shaking of a thermometer, there is good reason to suspect CTS. There are plenty of other tests such as Phalen’s Test and Tinel’s Sign – yet, despite the relative wealth of ways to diagnose CTS, there actually isn’t any kind of test to identify the precise cause CTS, and – except for patients suffering from underlying diseases – the biological mechanisms that create this inflammatory disorder remain unknown. 

It is a common story that CTS is caused through repetitive and often high-stress tasks that involve the wrists and hands – typing, using a computer mouse, manual labour to even playing the piano. While the correlation between CTS and tasks of this nature is undoubted, there is minimal evidence to suggest any clear causality.

In fact, most studies today indicate that CTS’ causes go above and beyond mere so-called ‘workplace factors’ and that they are rather linked to ailments that cause swelling in the wrist (osteoarthritis and rheumatoid arthritis) and others that obstruct blood flow (hypothyroidism and diabetes). We also see CTS pop up in clusters within a family, which suggests that something genetic is at play. Lifestyle also appears to play a significant factor, as those who smoke, drink alcohol excessively, consume excessive salt and who are obese all show increased risk of developing CTS. Women are also three times more likely to develop CTS than men, particularly after childbirth and during menopause.

Despite the range of medical, physical, genetic and life-style related items that are linked to an increased risk in developing CTS, their relationship is that of a correlation and not one of cause and effect. A modicum of clarity might be achieved, however, by overlapping both ends of the spectrum – the ‘workplace effect’ with medical/genetic/lifestyle factors. When somebody is susceptible to CTS – whether it be through genetics, a medical condition or an unhealthy or stressful lifestyle – and they also subject their hands and wrist to frequent, repetitive task, the likelihood of suffering from CTS will be at its greatest.

If you believe you are at risk of developing CTS, we would like to encourage you to seek medical advice on how to prevent it; if you believe you might already be suffering from it, we suggest you speak to one of our specialists for a suitable treatment. The earlier CTS is treated, the more likely – and easier – a full recovery will become.