What could be causing numbness and weakness in my left hand? i do have carpal tunnel syndrome, but this seems different, not as much pain, but a lot less sensation in my left hand.

Actually, : Actually, it's a myth that carpal tunnel syndrome is pain, particularly pain with typing. The hallmark symptom of carpal tunnel syndrome (cts) is numbness. Numbness in the thumb, index, long and half of the ring finger. The current best evidence is that cts is genetic (you we're going to get it no matter what you did) and--in my opinion--inevitably progressive. I warn my patients that surgery is necessary eventually to prevent numbness and weakness that it is permanent. Luckily the disease is very slowly progressive, so you should have some time to sort this out.

Well : Well carpal tunnel for one thing is associated with numbness in the hand. By numbness many people mean decreased sensation or tingling and it frequently occurs in the thumb, index and middle fingers and part of the ring finger. Weakness can occur form carpal tunnel as well especially in th thenar muscles, the large muscle group at the palm thumb side of your hand. There are many numerous other causes of numbness and weakness that are too many to mention. If you have carpal tunnel make sure your physician feels that your symptoms are due to that and not from another problem. There can be carpal tunnel and other problems that occur concurrently the video link and assh link gives some of the classic findings.