Causes of coughing and wheezing There are different reasons why your child may cough or wheeze. Possible causes include: Colds and other viruses – this is a very common cause of coughing. Choking – the coughing is sudden and the child has not been unwell. Croup – this tends to cause a barking, hoarse cough. Bronchiolitis – this is a chest infection, which can cause coughing and wheezing. Smoke – smoking around babies can cause them to cough and should be avoided. Hay fever – this may be caused by dust mites, animal hair or moulds. As well as coughs, other symptoms may include sneezing and a runny nose. Allergy – this can cause coughing after exposure to specific substances. Asthma – coughing tends to be worse at night or after exercise. The child may also wheeze. Whooping cough – a contagious infection, which can be prevented by immunisation. Pneumonia – this causes a sudden onset of cough, high fever and fast breathing: