Carpal tunnel syndrome is pain, tingling, and other problems in your hand because of pressure on the median nerve in your wrist.The median nerve and several tendons run from your forearm to your hand through a small space in your wrist called the carpal tunnel. The median nerve controls movement and feeling in your thumb and first three fingers (not your little finger).Pressure on the median nerve causes carpal tunnel syndrome. This pressure can come from swelling or anything that makes the carpal tunnel smaller.Things that can lead to carpal tunnel syndrome include:•Illnesses such as hypothyroidism, rheumatoid arthritis, and diabetes. •Pregnancy. •Obesity. •Making the same hand movements over and over, especially if the wrist is bent down (your hands lower than your wrists), or making the same wrist movements over and over. •Wrist injuries and bone spurs. •Smoking, because it can reduce blood flow to the median nerve. Carpal tunnel syndrome can cause tingling, numbness, weakness, or pain in the fingers or hand. Some people may have pain in their arm between their hand and their elbow.Symptoms most often occur in the thumb, index finger, middle finger, and half of the ring finger. If you have problems with your other fingers but your little finger is fine, this may be a sign that you have carpal tunnel syndrome. A different nerve gives feeling to the little finger. You may first notice symptoms at night. You may be able to get relief by shaking your hand.The sooner you start treatment, the better your chances of stopping symptoms and preventing long-term damage to the nerve.