Can anyone help me? I went to Oxygen assessment yesterday where my blood gas levels and sats were taken, and they were all better than previously, altho heart rate was very high. The o2 blood level was actually just above the threshold of someone getting extra O2 prescribed, and I can't understand since lung function is normally around FEV1 26%. I have had o2 at home since being diagnosed 7 years ago, and get very breathless. The nurses told me that being breathless doesn't necessarily mean that my o2 levels are low. The nurses were very nice and tried to explain but I must be a bit slow because I just can't get it! Can anyone help explain how this can be?