A lung abscess is a collection of pus and dead lung tissue inside the lung itself that results from a bacterial infection. It is sometimes called “necrotizing pneumonia” or “lung gangrene.”
Due to anaerobic bacteria (living without oxygen) found in the mouth, most lung abscesses occur when you aspirate (saliva goes down the windpipe). This can happen if you lose consciousness or have difficulty swallowing (dysphagia).
Other aggressive aerobic bacterial infections, such as Streptococcus, Staphylococcus, Haemophilus, can cause lung abscesses as well.
Symptoms develop slowly over weeks.