I've had similar symptoms for 3 months that all started after an episode of overexertion after running. I've also been given an inhaler, as well as start on Nexium (although I suspect my stomach acid discomfort may be because of the all the anti-inflammatories I have to take). They saw pericarditis, pericardial effusion, pleural effusion, atelectasis with me. I'm still being treated for pericarditis with anti-inflammatories. Was told I have pleuritis. It feels like my chest just locks up at times and I can't get a deep breath to go down and having awful right side chest pain intermittently...it almost feels like my chest on the right side gets so inflamed it closes up. They are still trying to work out what's wrong with me...next cardiac MRI on Tuesday. When you get out of breath does it feel like congestion is actually blocking your breathing tubes?