Might doctors tell when a patient is pretending to be sick?

Sometimes. : Some people get some sort of psychological gain from pretending to be ill. Others do it to get certain kinds of medications. Not usually hard to spot.

Usually: Doctors are trained to understand the constellation of symptoms that make up illness. Often, doctors are able to determine a patient is pretending, when the complaints or reported symptoms are not consistent with actual disease or disorders. However, there are times when even the best trained physician can be fooled.