Protein and Ribonucleic acids.
I would most likely associate this with either pneumonia (acute) or if patient is older some form of COPD; possibly Chronic Bronchitis.
The air begins to rise into the atmosphere. When air rises, it cools down and condenses into precipitation and clouds. This is why an approaching low pressure system means an increased chance for clouds, rain, or snow. It is called "low pressure" because as air rises, the air pressure is lower at the surface.
