I will not explain why I did go to the ER but I am grateful that I am alive and have medical insurance.  Afterwards, I did tell my family and close friends, "when in doubt about a medical condition, go to the ER.  Do not take a chance as your life could be at stake."  I think they all knew I was not referring to some of the things you mentioned.  Hence, I will never forget my ER experience and subsequent hospital stay.  No complaints from me.  And yes, if could somehow weed out the non-serious ER visits, that would be awesome.