Aspiration pneumonia is an inflammation of the lungs caused by inhaling large amounts of foreign material, such as food, liquid, vomit, or mucus. This can happen when a person has become weakened by an illness such as a seizure or stroke that affects his or her ability to swallow.

Pneumonia can make it hard to get enough oxygen into the bloodstream, which makes it hard to breathe. This form of pneumonia is more common in people whose immune systems are weakened by disease or medications. People who have aspiration pneumonia are usually treated with antibiotics in a hospital.