Pneumothorax Support Group
A pneumothorax (or collapsed lung) is a medical emergency caused by the collapse of the lung within the chest cavity. It can result from: a penetrating chest wound, barotrauma to the lungs, spontaneously (most commonly in tall, slim young males who smoke), chronic lung pathologies including emphysema, asthma, acute infections, chronic infections (tuberculosis, cancer).
I know you posted this a few months ago, but thought I'd reply anyway. As for me, I've had pain in the shoulder (an ache pretty high up) while the pneumo is healing. However, ever since my first pneumo (I've now had surgery and still have this), I have a dull ache on the side of my rib cage, which won't go away.
I hope that you're doing better now!