When I'm uncomfortable I get this not very sharp but persistant 'pins and needles' or 'bug bites' feeling in my upper back, back side of my neck, and my head. This doesn't happen 100% of the time, but it frequently happens when I'm working out (specifically cardio without a break), when im doing manual labor, or when I feel as though I'm being judged by the people around me. Haven't been able to find anything online. The pain is not to serious and usually goes away within 5 minutes.