In many cases, yes. Patients live with chronic conditions every day of their lives. They know what makes them better and worse and have probably done a whole lot of research into it, where the doctor might have had an hour long lecture 20 years ago about that specific condition (if at all). That's not to say doctors don't still have a role - they absolutely do, and know more about the body as a whole and how different things might work. But a good one will be prepared to listen and learn from your experience, do their own research, and if they're not sure, pass you onto someone who may be able to help more.