Healthy lungs are crucial to your child's well-being. The lungs can get infections that, when serious, can cause chronic and sometimes life-threatening illnesses.
Most cases of pneumonia follow a viral upper respiratory tract infection. Typically, the viruses that cause these infections (respiratory syncytial virus, influenza, parainfluenza, adenovirus) spread to the chest and produce pneumonia there. Pneumonia also can be caused by bacterial infections.