The illness causes violent spells of coughing that make it hard to eat, drink, or even breathe. The cough is accompanied by a high-pitched whoop that comes from gasping for breath after a coughing episode.
Whooping cough is caused by bacteria that attach to the cells in the airway.
The airway narrows and becomes inflamed. A substance is produced that inflames and narrows the airway. As a result, the lungs cannot clear the mucus. Pneumonia may develop. Other complications include ear infections, loss of appetite, and dehydration.