On the chest can cause puffiness first before muscular deterioration, and will lead to heart attacks. The body will purposely cramp up to contain cyanide into tissue instead expelling it to major organs which could instantly destroy that organ such as liver, kidneys, and spleen. Many of these disease are actually caused this way but for the most part, unconscious tension is how the body protects itself until it can expel the toxins safely through finger and toe nails. I know this for a fact as part of return to my youth is to release that tension from the years of abuse. And as expected, for the week or so, my left arm is cracking profusely. A cycle of tiny cracks, then major cracks, constantly repeating from the rotator cuff, and behind the deltoids. As it cracks, I feel the toxins moving from high to the lower parts of the arms as it works it's way towards the fingertips. Cracking from rotator to deltoids, to forearm, to wrist, to knuckles, then the finger nails become purplish, grow, and then a I cut them. I figured it all out so you do not have to.