I went to the doctor today with my girlfriend, and the doctor said that she had a virus but doesn't know which one and she should let the infection heal with some rest. The fact that the doctor didn't know what type of virus she has bothers me. Do physicians/biologists not know all the different types of viruses out there? Is it not possible to identify all of them?
It's difficult to identify the specific virus that a person may have. It would require pretty extensive testing to determine a specific virus. Doctors will usually diagnose based on symptoms.