DefinitionAspiration pneumonia is inflammation of the lungs and airways to the lungs (bronchial tubes) from breathing in foreign material.Alternative NamesAnaerobic pneumonia; Aspiration of vomitus; Necrotizing pneumonia; Aspiration pneumonitisCauses, incidence, and risk factorsAspiration pneumonia is caused by breathing foreign materials (usually food, liquids, vomit, or fluids from the mouth) into the lungs. This may lead to:A collection of pus in the lungs (lung abscess)An inflammatory reactionA lung infection (pneumonia)Aspiration of foreign material into the lungs can be caused by:AnesthesiaComaDecreased or absent gag reflex in people who are not alert (unconscious or semi-conscious)Dental problemsDisorders that affect normal swallowingDisorders of the esophagus (esophageal stricture,