MsP102,
Numbness and tingling in the extremities is due to some type of neuropathy. The most common cause in the developed countries is diabetes, but you stated you have had numerous blood tests and everything was okay. So, that sort of rules out diabetes and thyroid problems.
In the upper extremities, numbness and tingling at night or upon waking, is often due to positioning of the extremities while sleeping. We tend to flex the elbows up sharply and bend down the wrists, to put the hands up under the chin. Also, many times we use our hands to support the head or chin, placing compressive forces on the peripheral nerves. Or we put our hands up behind the head or pillow, which can cause problems such as thoracic outlet syndrome. Usually, this numbness and tingling gets better upon rising, straightening out the limbs, and shaking them out. Again, this is usually a peripheral neuropathy caused by positioning, which causes compressive forces on the peripheral nerves.
Unfortunately, sometimes patients present to their doctors in the early stages of disorders, before key symptoms show up, so a diagnosis cannot be made until some time down the road. Access to medical care is such, that patients are seeking care at earlier stages of disorders, before the classic symptoms show up or are detectable yet. So, with time, your symptoms should continue to progress and then, maybe, something will show up of the tests and a diagnosis can be made.
Keep track of your symptoms, as much as you can. Sometimes a journal is helpful, to see if there are any trends. Take the journal with you when you see your physician, as again, maybe showing will appear in the way the symptoms present themselves, that did not reveal themselves with just a periodic description.
It is very frustrating to know something is wrong, but not be able to figure out what is going on, for both patient and physician. Hang in there. With time, your symptoms will finally sort themselves out or medicine will progress and be able to diagnosis what your have with a better test. Unfortunately, there are still a multitude of problems that medicine just cannot figure out what is going on. We still know so little about the workings of the human body. Our knowledge has grown expentionally over the past couple of hundred years, but for all we know, the find that we are just scratching the surface.
Hang in there. Good luck.