Eh, also a sign of high BG.
Poor circulation, pinched nerve... are you on any meds?
If you want to be sure get some blood work done at the doctors office.
Then go pick yourself up a blood meter and 50 strips. Test your fasting BG (in the AM after you wake), before you workout - after you workout, when you feel strange, and at bedtime. Then when you have some time eat a single meal with 200g of carbs (nothing else) - measure before you eat, 1, 2, 3, and 4 hours after you start eating. You can also test before meals and 1, 2, 3 hours after you started eating - that info will tell you a lot.
I get numbness when my blood sugars are off but I also get it when I'm mineral deficient or dehydrated.