A cough is the forced, noisy expulsion of air through the narrowed glottis, generally caused by irritation of the mucous membranes of the respiratory tract.
It is the body's defence mechanism for expelling mucus or irritating pathogens from the respiratory tract.
Coughs have different causes and can take different forms. They can be dry, oily, acute or chronic.
Most of the time, a cough is caused by a viral infection such as the common cold, viral sore throat, bronchitis, nasopharyngitis or coronavirus. Or to a bacterial infection such as pneumonia or whooping cough, recognisable by its typical hoarse cough.
A cough can also be chronic, caused by allergy, gastro-oesophageal reflux, asthma or certain medications such as high blood pressure.












