If your child has been coughing for more than a week, see his doctor. "If a cough has gone on for three to six weeks, especially if the child is on antibiotics, then a chest X-ray may be needed," says Dr. Cardiello.
A persistent cough, particularly at night, can be a symptom of asthma. And a severe cough, followed by a whooping noise as the child struggles to inhale, can be an indication of pertussis, or whooping cough. A drop in immunization rates has led to pertussis outbreaks in recent years. Children may be at risk, even if they have been vaccinated.