In most cases, whooping cough symptoms appear seven to ten days after infection, although it may take longer in some cases. At first, they're mild and resemble a common cold, with symptoms such as a runny nose, fever, red or watery eyes, nasal congestion, and coughing. Signs and symptoms worsen after a week or two. Your airways become clogged with thick mucus, causing uncontrollable coughing. An intense and prolonged coughing attack may cause a red or blue face, extreme fatigue, vomiting, or a high-pitched "whoop" sound when breathing. The characteristic whoop, however, does not appear in all people. An adolescent or adult with whooping cough may only have a persistent hacking cough. It is possible infants do not experience a cough at all during this condition. They can struggle to breathe or even temporarily stop breathing.