Hi, Thank you for your question. It seems that your hand tingling & numbness symptoms could be due to injury to a nerve, pressure on spinal or peripheral nerves (neuropathy), vitamin deficiency, lack of blood supply due to cholesterol plaque from atherosclerosis in the extremities, viral infection and use of certain medications. In addition, atherosclerosis can also cause pain, numbness, and tingling while walking and they can also reduce blood supply and lead to numbness. Please consult your doctor to get all these possibilities evaluation in your case for further assessment. Hope this helps.
It could be a number of things which I wouldn't begin to guess.
No images done? (MRI, CT). There should have been especially if it is work-related.