It's also useful for having proper discussions. The doctors will discuss the details they're unsure about, which also helps you in discussing with the next doctor. If one doctor is very sure about one thing, and another isn't, that's a yellow flag.
The main symptom is contempt. You ask them a few questions or mention a second opinion, and their face turns into a scowl. Some are outright insulting, saying that X is a moron, without having enough information to make that judgement. Whenever I meet a doctor like this, I look for a second opinion, and very often it contradicts.
The next is buzzword. My child had a fever for a very long time and was hospitalized. A good pediatrician said "It could be Kawasaki disease... but it doesn't meet any of the other symptoms". A not very good one said "It's definitely Kawasaki disease, can't be anything else."
The third is well, passion. I know everyone hates the word, but I find a correlation. The worst doctors I've met are often trying to do anything except their job - they pitch unnecessary supplements, overcharge, talk about their stock investments. The great ones try to make you healthy; they end up undercharging, recommend cheap alternatives to their pills, volunteer for charity organizations, waive their consulting fees, and so on.
I realize this is a very subjective and biased way of looking at it, but it's worked well for me.
Some people can't suppress bad habits like using buzzwords. Maybe they have been taught to use them, maybe they are just too good at what they do to need worry about convincing you. Some people are great actors, and will make you believe they are truly passionate about their job. This is what I am talking about: https://medium.com/incerto/surgeons-should-notlook-like-surg...
1. Learn about the symptoms, diagnosis, and treatment of your health problem 2. Assess the severity of the health problem 3. Learn about the experience of other people 4. Get multiple opinions
Bonus: 5. Learn about multiple valid solutions 6. Find doctor's blind spots
While doing all that, you pay for healthcare, which includes all that. You pay a doctor to know no1, do the no2, remember no3. You then pay for multiple of them to do the same.
But then you still get to the point where you have to decide who to believe. And it would be easy if 4 of them say the same thing. You can be pretty sure they are right[1] because statistics. But what happens when they give multiple differing opinions, like here [2].
[1] https://www.youtube.com/watch?v=R13BD8qKeTg [2] https://digitalsmiledesign.com/files/Old-Website-Assets/PDF/...
