If you think carpal tunnel syndrome is caused by too much time typing on a computer keyboard, you’re probably incorrect, says Jeffrey M. Jacobson, MD, a Hand, Wrist and Peripheral Nerve Surgery specialist with Westchester Health Orthopedics and Sports Medicine, in his recent blog.
Many studies examining the connection between excessive computer use and carpal tunnel syndrome do not support a causative link between the two. In fact, in 2014, the AMA published that there is insufficient evidence to support linking keyboard activities with carpal tunnel syndrome,* states Dr. Jacobson. He explains that the most common cause of carpal tunnel syndrome is normal use of the hands over time. However, an underlying medical condition that causes swelling in the wrist and obstructed blood flow can also be the culprit.
Some of the most frequent conditions that are closely linked with carpal tunnel syndrome are:
- thyroid dysfunction
- fluid retention from pregnancy or menopause
- autoimmune disorders such as rheumatoid arthritis
- previous injuries such as fractures or dislocations of the wrist
Carpal tunnel syndrome explained
The carpal tunnel is a narrow passageway located inside the palm side of the wrist that is made up of bones and a wide band called the transverse carpal ligament. This tunnel protects the median nerve—a major nerve running from the forearm into the palm of the hand that controls sensation to the palm side of the thumb and most of the fingers (except the small finger). The median nerve also controls some small muscles in the hand which allow the fingers and thumb to move.
Carpal tunnel syndrome results when swelling or thickening from irritated tendons and nerves, or other inflammation, takes up extra space in the tunnel and causes the median nerve to be compressed. (In effect, it is a pinched nerve at the wrist.) Carpal tunnel syndrome can occur in one or both of your hands.
Swelling inside your wrist causes the compression in carpal tunnel syndrome which can lead to numbness, weakness and tingling in your fingers.
Symptoms of carpal tunnel syndrome typically include:
- pain, tingling or numbness in the hand, wrist or forearm (can be in combination)
- numbness or pain in the fingers (usually in the thumb, index, middle and ring fingers)
- decrease or loss of thumb function and hand dexterity
- numbness or pain at night, which can wake you from sleep
- symptoms can appear during daily activities such as driving or reading a newspaper or using your cell phone
- clumsiness with your hands and a tendency to drop things
You are more likely to develop carpal tunnel syndrome if you:
- are between the ages of 30 and 60
- are female (women are more likely to develop it than men) Certain conditions increase your risk for developing carpal tunnel syndrome, including
- have diabetes, hypothyroidism and/or arthritis
- eat a lot of salt
- have a sedentary lifestyle
- have a high body mass index (BMI)
Hand surgeons are particularly skilled at diagnosing carpal tunnel syndrome using these
- A physical examination includes a detailed evaluation to check for any other causes of numbness or nerve pressure. Your physician will look at your wrists for signs of tenderness, swelling and any deformities. He/she will check sensation to the fingers and certain functions of your hand.
- Nerve conduction studies are diagnostic tests that can measure the conduction speed of your nerve impulses. If the nerve impulse is slower than normal as the nerve passes into the hand, you may have carpal tunnel syndrome.
- An x-ray may be taken to check for other causes such as arthritis or a fracture.
- Laboratory tests may be ordered if there is a suspected medical condition associated with carpal tunnel syndrome.
Lower your risk of developing carpal tunnel syndrome
You can prevent carpal tunnel syndrome by making lifestyle changes that reduce your risk factors for developing it, including:
- stay at a healthy weight
- manage health conditions such as arthritis, diabetes, high blood pressure and hypothyroidism
- avoid or modify certain activities that put pressure on your carpal tunnel, such as weight lifting with poor hand form or long distance cycling with improper handlebars
To read Dr. Jacobson’s blog in full, click here.