Last edited 03/2020 and last reviewed 03/2020

This is a very non-specific symptom and can be described as a forced expulsive manoeuvre usually against a close glottis with an associated characteristic sound (1).

  • it can be elicited from the larynx, trachea or bronchi
  • helps out in clearing foreign objects and excessive secretions from the airways (1)
  • contains
    • inspiratory phase (an inspiratory effort) followed by
    • compressive phase (forced expiratory effort against a closed glottis) followed by
    • expulsive phase (opening of the glottis and rapid expiratory airflow) (2)

Cough is triggered when mechanical or chemical irritatants stimulate sensory cough-inducing receptors in the respiratory tract (1). Some common airway irritants include:

  • inhaled irritants like smoke, dust, dandruff
  • mucous
  • infections
  • allergens e.g. - animal allergens, pollen
  • chemicals (1)

Cough can be categorised according the duration in to:

  • acute – duration is less than 3 weeks
  • subacute – between 3 to 8 weeks in duration
  • chronic – lasting for more than 8 weeks (1).

Note that a persisting acute cough may develop in to a subacute or chronic cough (3).