First, get checked out!

Then, to give a short answer . . . it depends on where the pressure is and how it feels.  There is something called "referred" pain, and that means you feel the sensation somewhere else than where it originates.  The numbness and tingling sounds suspiciously like you are having and anxierty attack--the sensations are called "parastethias."  Anxiety (or panic) attacks can come out of the blue for no reason.  Does it feel like it's difficult to breathe as well?  Because when the attack happens, you are atually getting TOO MUCH oxygen.  But without the benefit of a complete blood work up and ECG (EKG), then there is no way of knowing how serious or benign your situation is.