I have been using this reference for several years. I can't practice medicine without it. I have made many esoteric diagnoses with it. It is extremely helpful whenever I have abnormal lab values, which do not seem to make sense at the time. Other lab references pale in comparison. Not only are abnormal labs explained, but the disease processes as well. I really like the way the book divides the elevated lab value from the decreased lab value, with their respective etiologies. An essential, excellent book!