Incorrect, delayed, or missed diagnoses have plagued physicians since the beginning of time. The result may be significant patient harm and medical resources wasted as the majority of all primary care physicians surveyed report that an average of five percent of their patients come under the category of difficult to diagnose, or CHALLENGING DIAGNOSES. It is more important than ever for patients to take the time to understand their own symptoms, assist in the zeroing in process of the diagnostic evaluation and collaborate fully with their physician in the sometime twists and turns leading to a final diagnosis.