The symptoms of whooping cough depend on the stage of the illness. On average, symptoms appear 7-10 days after being exposed to the Bordetella pertussis bacterium.In stage one, symptoms are similar to the common cold and may include:
runny nose
sneezing
low-grade fever
mild coughing
In stage two, coughing becomes more frequent and severe, especially in infants and children. The cough may sound like a “whoop” as the person tries to gasp for breath while coughing. During this stage, the thick mucus that develops in the respiratory tract can make it difficult to eat, drink, or breathe.
In stage three, coughing becomes less severe and less frequent and eventually ends.