Pneumonic plague is a serious infection caused by the bacterium Yersinia pestis, which primarily affects the lungs. It is a more severe form of the plague and can spread from person to person through respiratory droplets when an infected person coughs or sneezes. Symptoms include fever, chills, and difficulty breathing, and it can progress rapidly if not treated promptly. This type of plague is part of a larger group of diseases known as the plague, which also includes bubonic plague and septicemic plague. While pneumonic plague is rare today, it can still occur, especially in areas where the bacterium is present in wild rodent populations. Early diagnosis and treatment with antibiotics are crucial for recovery.