I saw this message thread a couple of months ago....I felt the need to come back and try to find it and opened an account just to reply to all of you. I had the same issue - started a year or so ago and seemed to come from nowhere. Thought for sure it was iron related. I have been taking supplements. It seemed to work. It is the kind of thing that comes and goes for sure. I run too, which makes dealing with it harder. Then of course the more I think of it, the more I have to yawn. Well......this week is is getting noticeably better every single day. WHY? I think I know - and will leave this here and let you all decide for yourselves. I have had an ongoing issue with a compression in my shoulderblade/neck. MUCH massage therapy wasn't helping. I was working out through the discomfort but it was basically chronic. I saw an advertisement for a local chiropractor so decided to go see him. I have had the scans and the x rays and I see for myself how messed up my spine is. I have had three adjustments and my need to yawn is getting BETTER. I still do - especially if I overthink it. But it doesn't ache at the bottom, and the yawn gets "over the hill". The adjustments are HELPING. I didn't think I would find a solution and after reading your posts I thought I would be like you. But it is HELPING. I hope you consider it. It could help you too. Read up on how spine and lungs are related.