question: I hate to make this lengthy but here it goes.  A couple months ago i was watching a movie with family and was having a perfectly great day.  After the movie as soon as I stood up I experienced a sudden pain/discomfort in my lower stomach area (just bellow the belly button), my heart started pounding very hard and rapidly, and i also had the shakes along with some nausea.  I could barely walk or speak.  After a few hours of this it eventually went away.  But now it's happening everyday/night, just not as severe.  It's an almost constant discomfort/pain in the same stomach area and at night the pain/discomfort worsens along with an increased heart rate.  This has been going on for several days and it's really troubling me. What could possibly be wrong with me?  I am 21 year old male with no previous medical conditions nor am I on medications.I did attempt to go to the ER the first time I had this (about 2 years ago) but by the time the Dr. saw me the "episode" was over with and I received Zero advice.  These symptoms i used to get at what it seemed to be random times.  Sometimes a month apart and other times many months apart.  But now it's everyday especially at night.Please I beg you, what should I do?