Is it possible? Yes. Is it likely or common? Not really. Typically, if you have all the symptom of one or two things, you probably have those one or two things, especially if they are co-morbid conditions. It's far less likely to have, for example, 10 different specific symptoms from 10 different things. Diagnosticians usually go for the fewest potential causes of a given set of symptoms. If something is perfectly explained by 2-3 things, very seldom is it actually more like 6-7 things sharing the symptoms in some complicated overlapping manner. Exceptions definitely happen, but it's usually the simpler answer.