What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome is characterized by numbness and tingling in the thumb, index, and middle fingers. It often involves both hands, and can be associated with cubital tunnel syndrome which causes numbness in the small and ring fingers. It commonly will wake you up at night with burning and pain, and may require you to shake your hands to get relief. Late findings include poor sensation in the fingers, dropping small objects, loss of dexterity, and atrophy or wasting in the thumb muscles. Carpal tunnel syndrome is very common, but it is important not to confuse it with other medical problems such as tendonitis, arthritis, or overuse syndrome.
The carpal tunnel is a space in the wrist where the median nerve and 9 tendons pass. It is bound by bones on 3 sides and the transverse carpal ligament. Anything that increases swelling within the tunnel can increase pressure on the median nerve and inhibit blood flow and lead to injury. Since the median nerve innervates the thumb, index, middle, and half the ring finger, any injury can cause symptoms such as pain, numbness or tingling in these fingers. Severe damage can cause weakness in the thumb muscles over time.
Common risk factors include age over 50, female gender, and pregnancy. Underlying medical problems can such as diabetes, hypothyroidism, rheumatoid arthritis, and fractures can make you susceptible. Exposure to vibration and repetitive motion can exacerbate the underlying condition, but not necessarily cause carpal tunnel. Repetitive stress syndrome is a separate entity from carpal tunnel and requires non-surgical treatment, mostly involving hand therapy and workplace modifications.