Oh, yeah--- at least it's normal for me. I can sleep 16 hours a day. Don't know what my lung capacity is but I can't walk to the bathroom and back without needing an inhalor. Am 87, have had emphysema 10 years or so. Weak, tired, can hardly walk , trying hard to think of something good , not to be depressed.

I do not believe that Lung Function plays a major role in determining how well you cope doing daily activity, unless it has reached the stage that nothing can be done either......

You need to do a bit of a lifestyle change and keeping to the SOB means a good exercise program n daily routine, to build up endurance...Without this even the most basic tasks will seem impossible as we are using so much energy just to breathe....

That is why we suffer overwhelming fatigue.....

I was diagnosed with 50% lung function many many years ago and I was exhausted the whole time, it took a while to get the right inhaler meds and after that I was able to begin exercising enough to get to the point I could attend a Pulmonary Rehabilitation course.

To being you may think its impossible to exercise but any little bit you can do on a regular basis helps stop further deconditioning which will only make the condition worse. Start small 2-3 mins walking back and forth 4-6 x daily, its ok to be short of breath, just pause recover and continue. Its ok to feel exhausted after, you can have a little sleep, set the alarm during the day so you don't sleep longer than 2 hours at a time, then do some walking back and forth, stretches etc. If you don't do anything you will get worse so start small and work up from there so that you may reach a point you can attend a pulmonary rehabilitation course or another exercise course that your doctor may recommend.

Good luck.