Dr said i have carpal tunnel as my hands go numb when i sleep. my feet have also started to go numb but goes away if i change position,what could itbe?

Numbness: Numbness in the feet can be caused by a similar problem to Carpal Tunnel called "Tarsal Tunnel." But there are many other causes of numbness, including nerve damage or Neuropathy, Neuromas or other nerve impingements, poor circulation, etc. If you want to know for certain, you can visit a Neurologist who can perform an EMG/NCV study to try to isolate the cause of your problem.

Hands & Feet ?: The symptoms you describe are concerning in this respect. There are many, many reasons why a hand or a foot can go numb. You are saying that initially both your hands were affected and that now both your feet are also affected. The list of all the potential causes for your symptoms has just gotten more complicated. I suggest that you see a neurologist for his expert opinion and recommendation.