I've had minor irritation in the lung, sort of a sharp discomfort. And it seems to be a fairly common complaint in the health forum. I originally thought it was my heart since it exists in my family, but after deliberately relaxing and dismissing it as paranoia and working out and eating healthy, I don't get it anymore.

IT could be a simple irritation in the pleural lining of the lung, which is exacerbated by stress and paranoia when stoned. Or it could be anxiety, but definitely get a doctor's opinion.