Pertussis in a child, without whooping. Pertussis causes paroxysmal coughing; only about half of patients develop classic whooping.

In this recording, the child coughs without inspiration until she has emptied her lungs of air, then breathes in. There is a slight pause between the paroxysm and inspiration. In severe cases of pertussis, this pause may be long enough to qualify as apnea; children may become cyanotic, and the apnea may be life threatening.