I saw your comments on Annie59's post. I think you know what I'm going to ask . . . has your primary doctor checked your vitamin B12 levels?! Numbness in extremities is a huge red flag for that.
They should also check your homocysteine level. Some disagree about this but your B12 number could be, for example, 400 (normal range) and if your homocysteine is elevated, that means your body is not getting enough of B12. Methylmalonic acid, another simple blood test they can do, might be elevated too.
My B12 deficiency came on slowly. I passed it off as being tired from working too hard (1997-99). By the time I was diagnosed, I had numbness in my hands, ankles/feet and face, was so tired I couldn't stay awake, felt faint, had palpitations, signs of dementia and just felt like the life force was being sucked out of me. Do you have any other signs that the numbness? Is it equally on both sides? Have they checked your lower back?
A B12 deficiency is very common, as is a Vitamin D one. With B12, people often don't have enough stomach acid to properly digest their food and not enough of the B12 is absorbed. I'll stop there because I can go on and on about this.
Please get it checked out. If it is a B12 def., the longer you go with one, the longer it takes for the peripheral nerves to recover.
Annie