The symptoms of whooping cough develop in stages. During the initial phase, which can last one to two weeks, the illness resembles a common cold with a runny nose, sneezing, mild cough, and low-grade fever. As the infection progresses, the cough becomes much more severe, often occurring in long, uncontrollable fits followed by the characteristic high-pitched “whoop” sound. These coughing episodes may end in vomiting, exhaustion, or even difficulty breathing. The fits can be frequent, especially at night, and may persist for several weeks or longer. In young babies, the illness can be particularly alarming, as they may not cough at all but instead stop breathing temporarily or turn blue. It is essential to seek medical attention if whooping cough is suspected, particularly in infants or vulnerable individuals.