You’re right and many doctors don’t know where to start bec they have no idea what they’re dealing with. In my case, the primary symptom was a horrible, hacking cough that went on for 6 months, masking the impending kidney failure. The pulmonologist ran every test he knew of and even repeated some before throwing his hands up. My primary said I know you’re sick but I don’t know even where to refer you. There are some broad blood tests that help doctors narrow down the search for the problem. They just need to know which tests to ask for. It’s a problem.