can be from the fight or flight response which limits bloodflow to some body parts. read about it on the net
most anxiety sufferers get effected by the fight or flight response and should learn about it
The first time I experienced numbness I had it in both my hands and feet. I was going through a withdrawal of clonazepam too quickly and my anxiety was at about 15/10. It scared me so much, my hubby was holding my hand and I couldn't feel it.
In everyday anxiety if it gets bad I often get a numbness around the side of my mouth and part of my face.
the fight or flight response reduces bloodflow to the hands, feet and head, this is to reduce bleeding when you fight or flee to save your life
as mentioned, we all should study the effects of it on the net