Tingling leg / foot

I joined the gym about a year ago.  After i had been there for a few months i started using the ellpitical on a regular basis.  I would notice frequently that my right foot would start to tingle and feel asleep when i did this exercise but would always go away after i was done.  One day the tingling didn't go away and lasted for almost two weeks before i went to the urgent care doctor.  They really didn't come up with any reason.  Almost 9 months later it still continues but it comes and goes, almost daily.  Where it used to be a very prickly pins and needles feeling, it is now a more dull falling asleep feeling.  It usually starts in my foot/ankle area and moves up into my lower leg but doesnt' seem to move up past my knee.  My family doctor has run many blood tests for B-12 deficency, diabetes, lupus, etc and hasn't found anything.  The last thing she told me was if it got worse or spread they would investigate further for things like MS, which obviously freaked me out.  I would like another doctors opinion on what the cause of this could be and if MS is the most reasonable next possibility.

[Enoch Choi, MD]

you could be experiencing pinching of a nerve due to too constrictive footwear

MS is unlikely but possible

consider a lumbar MRI to see if pinched nerves from disc disease could be contributing