DeQuervain’s tenosynovitis, also known as numb thumb, is an orthopedic issue cropping up in people who are glued to their phones.
Holding the hard edge of your phone with the base of your thumb puts pressure on the nerves that supply feeling to your fingers, says Michael Hausman, MD, chief of hand and upper-extremity surgery for the Mount Sinai Health System in New York City. That can cause numbness or soreness at the base of the thumb as the tendons become inflamed.
To avoid extra stress on the joints and tendons, stretch and straighten your fingers throughout the day and try to avoid bending your thumb all the way down, he says. Instead of wrapping your hand around your phone, you’re better off getting a case with a grip on the back and cradling it in your palm.
“Numb thumb is unlikely to cause permanent damage unless someone uses an extremely tight and painful grip for a long period of time, which could conceivably damage the nerves,” Hausman notes, but it can cause unnecessary discomfort.