Yup. Most doctors are basically glorified pigeonholers. Grab pigeon (patient), find matching hole, put pigeon in hole and read the directions on the hole.

Unfortunately, when there isn't an obvious matching hole they tend to stuff them in wrong holes (there are conditions for which getting the right diagnosis often takes years), or when they don't see any appropriate hole they stuff them in the "crazy" hole. And the doctors are very reluctant to take a pigeon out of a wrong hole, especially if it's the crazy hole.

I recall a thread on here from some years back, diagnosis: anorexia. Real diagnosis: partial gastroparesis. She didn't want to eat because her body wasn't pushing the food on down the system properly and eating was very unpleasant!