Many people make a very fast decision to have ETS. A quick 1-hour (half an hour each side) minor surgical procedure that often doesn't even require overnight stay sounds miraculous. However, this surgery can sometimes lead to long-term turmoil on the internal networking of your body. After all, there must be an evolutionary reason as to why the sympathetic nerve chain is in a location where it can never be damaged unlike virtually all other components of your body. Humans can easily damage external parts of their bodies through physical injury. In addition, most internal organs such as the brain, heart, kidney, liver, and lung can be damaged by cancer, diet, drinking, smoking and the like. However, to my knowledge, the sympathetic nervous system (or more specifically, the thoracic ganglions) can almost never be physically damaged without surgical intervention because it is deep inside the chest and made up in a rope like manner that cannot break easily. A bad diet, smoking, drinking and so on can also not damage the sympathetic nervous system.