Coughing occurs when nerve endings in the airways become irritated, causing a message to be sent to the cough centre in the brain. A cough begins with a deep breath in, at which point the opening to the respiratory system closes and air gets trapped in the lungs. Next, the muscles normally involved in breathing, such as the diaphragm, forcibly expel air from the lungs.

Air travelling out of the lungs moves very fast, which helps to remove whatever was causing the irritation. There are many different causes of coughs, so be sure to ask the customer about their symptoms. Use the WWHAM questions, but also enquire about the nature of the cough.

For example: did the coughing begin gradually or suddenly? Do you think the onset was related to an infection, such as a cold? Are you coughing during the day? Is it worse at night? Do you have any other symptoms?

The customer's answers to these questions will help to determine who should self-treat and who should speak to the pharmacist.