It can happen while you're cycling, driving a car, speaking on the phone or working at a computer. It can also wake you up at night: Your fingers tingle or go numb, and they, your hand or wrist may ache.
While it's normal for your hand to "fall asleep" on occasion, frequent such occurrences can be a sign of carpal tunnel syndrome (CTS). Here are three questions and their answers regarding this common nerve disorder:
What's carpal tunnel syndrome?
The carpal tunnel is a narrow passageway on the palm side of the wrist, bound by the carpal bones and traversed by nine flexor tendons and the median nerve, which controls movement and sensation in the forearm, wrist, hand, thumb and fingers - except the little one - explains hand surgeon Dr Michael Fendler.
If the median nerve is compressed, its signals are blocked. One possible cause is overuse of your wrist. The symptoms are especially felt in your thumb, index and middle finger, and pain can radiate into your forearm. They often occur at night because many people sleep with their wrists bent, Fendler says.
If the condition is allowed to progress untreated, in particular the muscles at the base of the thumb get weaker and atrophy. As a result, certain actions with your hand become difficult, such as unscrewing a bottle top.
Then, at the latest, you should see a doctor, otherwise the median nerve may be permanently damaged and your fingers constantly numb.
Who's at heightened risk of developing CTS?
It occurs most often in people aged 40 to 70 and is more common in women than men, according to Fendler. Also at heightened risk are, for example, people who regularly use vibrating tools, such as a pneumatic hammer.
Further risk factors include medical conditions such as diabetes and rheumatoid arthritis as well as hormonal changes during pregnancy and the menopause.
How is CTS treated?
If the condition isn't too advanced, wearing a wrist splint at night can help relieve pressure on the median nerve by keeping your wrist straight, says Fendler.
In addition, sufferers should be careful not to overstrain their wrists. If you work at a computer, adjust the seat of your chair so that your elbows are at keyboard height and you don't have to bend your wrists. A mouse pad with a wrist rest can help too, points out Fendler.
Another tip: During long phone conversations, switch hands now and then.
It's also a good idea to stretch and bend your wrists and "shake out" your hands a few times a day, which can help relieve symptoms. A corticosteroid injection into your wrist can bring temporary relief as well, as it brings down swelling around the median nerve, easing pressure on it.
In severe cases of CTS when conservative treatments are ineffective, surgery may be needed. The surgeon will cut the ligament and remove tissue pressing on the median nerve.
