The reasons are:
-Rheumatoid Arthritis
-Pregnancy
-Osteoarthritis
-Diabetes
-Amyloidosis
-Hypothyroidism
-Tumors and similar conditions
-Fluid retention
-Swelling or inflammation of the tendons
Some of the things which you can do to avoid carpal tunnel syndrome
-Regular exercise for your wrists and hand
-Avoiding too much stress on your hands and wrists
-Follow a proper posture while sitting on your computer
-Usage of acupuncture or osteopathy
-Get your arms, wrists massaged
-Avoid pressures on your wrists. Use your elbows and shoulders instead
-Take short breaks during work
-Warm up before you start your work
-Avoid sleeping on your hands
-If you are a regular user of the computer you can set your keyboard in a flat position rather than a slanting position
-Do not rest your wrists on the keyboard
-Try using a mouse pad and avoid resting it on the desk
-Type softly
-Sleep in an upright position to avoid pressure on your nerves
-Don't tie the hand bandage very tightly
Some simple remedies for Carpel Tunnel Syndrome
-You can apply ice pack for relieve
-Usage of acupuncture or osteopathy
-Get your arms, wrists massaged