A few reasons. Sometimes when lying flat the pressure in my chest is too great, so I sit up, sometimes I wake up suddenly gasping for air, sometimes I get this overwhelming wave of just dysfunctional breathing and start this involuntary rapid breathing. It's attacks like this that feel the worst.

For me the definite things seen on my scans have been subsegmental bibasalar atelectasis, pleural effusion, and "possible" pericarditis. All of my symptoms started on Feb 23, 2019 after I had gotten really, really overexerted due to running. Since then I have actually felt like I'm in a perpetual state of getting overexerted--but all the discomfort I'm feeling is only on my right side. You know that feeling when you run and you can't get a full, deep, satisfying breath after? It is like something in your chest is just saying no I'm not going to let you take a deep breath. That's what every day has felt like along with chest pain. The doctors have called all of this pleurisy. I am researching diaphragm dysfunction along with pleural effusion. I think it's possible I may have had some sort of pleural effusion prior to running which caused the atelectasis. (Atelectasis is caused by pressure on the lungs.)