A persistent cough can be very annoying but why do we cough?
Coughs are often caused by excess mucus or other irritant matter from external sources – dirt, smoke, household cleaners – lying on the surface of the respiratory tract, and your body is trying to expel them out of your system.
The body uses the mucous membranes as an exit route for toxins. When a bug infects you and your immune system attacks it, dead bacteria and dead immune cells can be pushed out via mucous secretions. Also, if other eliminatory organs such as the bowel aren’t working well, then some toxins may be diverted to the respiratory tract to be offloaded through these membranes.