The NHS has primary (GP) and secondary (hospital) care. Except in emergencies, we always visit our GP first. They refer us to “the hospital” as necessary. They might also book tests in the meantime.
It would be expensive and ineffective if everyone self-diagnosed and went straight to a hospital specialist, because many people would misdiagnose their condition and see the wrong specialist. In the main, the primary-secondary split is sensible.
As regular readers know, I had a frozen shoulder and discussed different approaches with my NHS consultant. I have already written up one of his ideas to improve productivity, reduce waiting times (and pain) and cut costs. Here are his two other ideas, bundled together. One in five people has a frozen shoulder at some point, so these ideas is intrinsically important to patient outcomes and NHS productivity, and might generalise to other conditions.