Many anxiety sufferers really do suffer because of a potential chemical imbalance, heredity, excessive stress, substance abuse, or other mental ailments.  However, there is a group of people that have an anxiety disorder caused by an actual medical condition.  In some people there really is a phyiscal basis for their anxious suffering and this is why regular medical screenings are important. Now statistically it is very difficult to say what number of anxiety sufferers have anxiety because of a pre-existing medical condition.  But the fact