Aspiration pneumonia is an inflammation of the lungs caused by breathing in 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 the ability to swallow.

Pneumonia can make it hard to breathe. This can reduce the amount of oxygen that gets into the bloodstream. This form of pneumonia is more common in people whose immune systems are weakened by disease or medicines. People who have aspiration pneumonia are usually treated with antibiotics in a hospital to prevent or treat an infection.