What is carpal tunnel syndrome? Carpal tunnel syndrome is a common condition that causes pain, numbness, and weakness in the hands and wrist. It occurs when there is increased pressure on a nerve called the median nerve. This nerve provides sensation to the thumb, index and middle fingers, and to half of the ring finger. The small finger is typically not affected. The median nerve also provides strength to some of the muscles at the base of the thumb.
Symptoms usually begin slowly and can occur at any time. Early symptoms include numbness at night, tingling, and/or pain in the fingers (especially the thumb, index, and middle fingers). In fact, because some people sleep with their wrists curled, nighttime symptoms are common and can awake people from sleep. These nighttime symptoms are often the first reported symptoms. Shaking the hands helps relieve symptoms in the early stage of the condition.
Common daytime symptoms are tingling and decreased feeling in the fingertips. Patients also report difficulty handling small objects, grasping a steering wheel to drive, holding a book to read, writing, and using a computer keyboard.
As carpal tunnel syndrome worsens, symptoms become more constant. Weakness in the hand, inability to perform tasks that require delicate motions (such as buttoning a shirt), and dropping objects begin to occur. In the most severe condition, the muscles at the base of the thumb visibly shrink in size.
Some of the predisposing factors include: diabetes, obesity, pregnancy, hypothyroidism, and heavy manual work or work with vibrating tools. There is, however, little clinical data to prove that lighter, repetitive tasks can cause carpal tunnel syndrome. Other disorders such as bursitis and tendinitis have been associated with repeated motions performed in the course of normal work or other activities.