Coughing is a reflex action started by stimulation of sensory nerves in the lining of the respiratory passages – the tubes we use to breathe. When a person coughs, there is a short intake of breath and the larynx (the voice box) closes momentarily. The abdominal and chest muscles used for breathing contract, which in turn increases the pressure needed to drive air out the lungs when the larynx re-opens. The resulting blast of air comes out at high speed, scrubbing and clearing the airway of dust, dirt or excessive secretions. Coughing is a common symptom when the airways are ‘tight’, as in asthma.
The cough reflex is a vital part of the body’s defense mechanisms. Normally, the lungs and the lower respiratory passages are sterile. If dust or dirt get into the lungs, they could become a breeding ground for bacteria and cause pneumonia or infection in the breathing tubes.
What causes coughing?
Coughing usually means there is something in the respiratory passages that should not be there. This can be caused by breathing in dust particles in the air or when a piece of food goes down the wrong way. It could also be a sign that an infection in the lungs is making the respiratory passages produce phlegm.
Coughing can be provoked by:
Coughing is more efficient when preceded by a full intake of air.
For this reason, patients with weak muscles, poor coordination of airway closure and re-opening, or who have airflow obstruction (as in COPD) will have a poor cough and be susceptible to complications including infection in the lower respiratory tract and pneumonia.
How can coughing be treated?
More coming soon