Hi, I am a 50 yr old woman with athsma (not severe) Anemia,(borderline 10-11 on a good month) and an MVP. I breath fine during normal activity. I can go to the gym and enjoy long walks without difficulty. However, when I fly longer than 3 hours I find it very difficult to get enough oxygen, I cannot sleep on long flights and my heart races on planes as well as when I am at higher altitudes (such as skiing in Colorado) Or hiking in the Adirondacks. My family thinks I make up my discomfort. Is there a scientific connection? If so what can I do to prepare better? We traveled to Italy last summer and after 10 hours of flying I felt awful. Partially lack of sleep, but I just felt gray. I am concerned about a flight to Vietnam in Dec.