When I was diagnosed with Stage 3 COPD 4 years ago, they put me on 3 liters of oxygen and told me my blood oxygen should read between 88 and 92. Since that time I have lost 70 pounds and have exercised an hour 5-6 days a week. My blood oxygen is now between 95 and 98. During my most recent trip to my pulmonologist she said that was too high, that it should be 88 to 92 and told me to take my concentrator down to 2 liters. I did that and immediately slept off and on all day and my muscles were fatigued. This was the result in just one day. So, I turned the concentrator up by .5 and am now at 2.5 liters. My blood oxygen is now between 94 and 97. Probably still too high. I’ll turn my concentrator to 2.25 and see how that works. I know that too high a reading can be harmful but honestly I can’t live with the muscle fatigue and drowsiness. Anyone else have this problem?