You may have a condition that isn't responding to treatments by your local physicians. At this point, it may make sense to go to a research center like the Mayo Clinic in Rochester, Minnesota.
Ask your doctor for a referral to the Mayo Clinic. After you and your doctor determine that you want to and can go, then your doctor will get in touch with the Mayo Clinic. The clinic will schedule a time and send you a letter. You may be put on a waiting list. If the appointment is not convenient, then you can call and reschedule the appointment.
Complete the papers that the Mayo Clinic sends you. Take these papers with you when you go.
Get all of your medical records from doctors who have treated you for the condition that you are seeking advice for. Make reservations at a hotel in Rochester. The Mayo Clinic will tell you to be prepared to stay 6 days. Rarely does anyone stay that long. A 4-day reservation should suffice. Arrange your finances.
Travel to the Mayo Clinic. Register at the appointed time at the clinic. Take an additional $1,000. Often the Mayo Clinic will repeat tests that have already been done. If your insurance does not cover all of the costs, then you are expected to pay, if not all, a certain percentage. At this point, your tests, past medical records and current assessments will be assembled and reviewed, and the cadre of physicians will come up with a diagnosis.
Listen to the doctors who present you with their findings. They will suggest a course of treatment. Sometimes it will require coming back to the clinic, sometimes it will require Mayo's working with your local doctor and sometimes it will require sending you to a highly trained specialist who is closer to you than the Mayo Clinic. Pick the course of treatment and action that you are the most comfortable with.