Pertussis, commonly known as whooping cough, is a highly contagious respiratory disease caused by the bacterium Bordetella pertussis. It primarily affects young children but can also infect adolescents and adults. The illness is characterized by severe coughing fits that can make it difficult to breathe, often leading to a distinctive "whooping" sound when inhaling. Vaccination is the best way to prevent pertussis. The DTaP vaccine is recommended for infants and young children, while a booster shot, known as Tdap, is advised for older children and adults. Early diagnosis and treatment are crucial to reduce the severity of symptoms and prevent the spread of the disease.