Anxiety is a very real and unpleasant physiologic condition, created by over-stimulation of the adrenal glands.  These tiny organs which sit above the kidneys (“ad” above, “renal” kidney) secrete potent hormones including cortisol and adrenaline.  Adrenaline, as you know, is the “fight or flight” hormone, which can cause intense core vaso-constriction as blood is shunted to the major running muscles and to the brain.  This temporary but extreme shift in blood flow dynamics creates many very real symptoms,