Hi,, I live in Canada and have had copd for the past 9 yrs (diagnosed as severe) and about 2 yrs ago I got fibromyalgia. I am on 0xygen 24/7, still walk, but am now experiencing migraine-like headaches with nasau. I sometimes wake up with the headaches, but mostly they just pop up whenever and. Can leave suddenly ,or hang around for days. Anyone else experience these. Don't believe I am retaining carbon dioxide.