I know this isn't always the best answer, but if you need real medical advice - see a doctor. Not the internet.

No, see both. LLMs are great for second opinions, as long as you give it the relevant info and don't try to steer it. Even though we all know we're supposed to get second opinions on medical things, we usually don't bother because it's too expensive in both time and money.

If it could be an emergency, see a doctor.

If you need a second opinion, ask another doctor. My question would be, do you tell him "Here's the first doctor's diagnosis, do you agree?" or do you go in cold and see what he comes up with?

You gonna pay for it?