My 28YO daughter has been fighting fatigue, among other symptoms. In earlier this year, her PCP learned that her O2 drops periodically. In the walk test, 97 down to 80, but other times into the 60's. Cardio function looks good, and she'll see a pulmonologist next month. After months of back and forth with insurance she is finally on Oxygen. Her doctor recommended she seek treatment someone at the Mayo Clinic, Phoenix. Do any of you have good experiences there?