A number of things can cause a lung abscess, including: Not being able to cough: This often happens as a result of: Anesthesia Alcohol or drug use Nervous system diseases Sedation Poor oral health: People with gum disease are more likely to get an abscess. Your immune system isn’t working well: This can let in germs that aren’t usually found in your mouth or throat, like fungi or the bacteria that cause tuberculosis, strep throat, and MRSA.