A cough is an important defence mechanism that aims to clear the airways of secretions and prevent entry of foreign bodies and irritants to the lungs. A cough is one of our strongest reflexes. It is a normal response when we are well but it also occurs in a number of respiratory (lungs and airways) illnesses. A small number of people have a persistent cough that requires a specialist opinion.
Chronic cough is a cough that lasts longer than eight weeks. It is present in 3% of the general population. Chronic cough is often thought of as an insignificant problem but can be associated with distressing symptoms such as joint and muscle pain, chest pains, fainting, incontinence, disturbed sleep, and social embarrassment.
What causes chronic cough?
There are cough receptors in the upper airways that when stimulated cause the cough reflex. Most cases of chronic cough are associated with increased sensitivity of these receptors, especially if the cough is dry.
The cause of most cases of chronic cough in patients with normal breathing tests who are non-smokers and have a normal chest x-ray is asthma, reflux (acid coming back up your throat from your stomach) and rhinitis (inflammation of the nasal passages) or a combination of these.
Some people however have no underlying diagnosis or cause. It often starts after a virus or some other normal reason to cough, but remains after the initial event resolves.
Coughing can be caused by dry irritable airways, increasing the sensitivity of or ‘roughing up’ the cough receptors. The resultant coughing and throat clearing continues leading to an unhelpful cycle.
Chronic mouth breathers and people with disordered breathing patterns fit into this category due to the dry air they inhale and high rate of their breathing.
Treatment involves proven strategies to suppress cough and throat clearing and then improving breathing pattern to reduce the underlying stimulation. If there are secretions as well, then clearance is also addressed.