What Is Carpal Tunnel Syndrome and What Causes It?
Activities requiring repetitive motions like knitting, working with power tools, or using a mouse may cause pain, numbness, or tingling in fingers and hands. If you experience any of these sensations, you may worry that you could have Carpal Tunnel Syndrome, a common condition that may arise if a specific nerve in your wrist becomes compressed.
The nerve, which is called the median nerve, provides sensation to your thumb, index finger, middle finger, and ring finger. It runs down your arm and into your hand through the carpal tunnel, a passageway in your wrist formed by the surrounding carpal bones. The carpal tunnel is covered on top by a ligament – specifically, the transverse carpal ligament.
If your carpal tunnel narrows or the surrounding wrist tissue swells, it can put pressure on your median nerve. When the nerve is entrapped in this way, it can cause pain, weakness, numbness, tingling, burning, or even a sensation that feels like an electric shock.
At first, Carpal Tunnel Syndrome symptoms may only arise briefly after something puts pressure on your median nerve. Over time, the weakness, burning, or tingling may happen more often, and it may last longer each time it happens. Eventually, the symptoms may become constant for some people who don’t seek treatment for Carpal Tunnel Syndrome. They may find it difficult to work, drive, cook and do many enjoyable activities that involve the hands.
What are some common causes of Carpal Tunnel Syndrome?
- Awkward hand or wrist positioning while sleeping. According to the American Academy of Orthopedic Surgeons,1 sleeping with your wrists curled downward may contribute to Carpal Tunnel Syndrome over time.
- Wrist fractures or sprains. A wrist injury may cause swelling, which could impact the median nerve.
- Rheumatoid arthritis. This chronic condition causes inflammation and swelling, affecting any joint but is more common in the wrist and fingers.
Certain conditions may put you at greater risk of developing carpal tunnel syndrome, including:
Women are more likely to have smaller carpal tunnels than men, since they typically have smaller wrists. Women are three times more likely2 to be susceptible to Carpal Tunnel Syndrome, according to the National Institute of Neurological Disorders and Stroke.
A family history of Carpal Tunnel Syndrome
The extra fluid that circulates in a pregnant woman’s body may cause swelling that contributes to median nerve compression.
Other health conditions
Diabetes, underactive thyroid, lymphedema and menopause may be associated with a greater risk of Carpal Tunnel Syndrome.