Secretion/sputum/phlegm is a type of mucus produced by the Goblet cells which are found within the airways lining. The Goblet cells combines with Celia to fight bacteria, as they trap, capture, and hold foreign substances so that they can be removed from the airways.

A small amount of mucus is produced naturally each day.

Consequences of Secretions in Airways

• A build-up of secretions can lead to increased difficulty in expectoration
• Reduced space for airflow within the airways causing breathing difficulty and lung decline
• Increased risk of respiratory tract infections which can further damage the lungs
• Inflammation causes narrow airways that brings about poor quality of life
• Combined narrowing of the airways and increased secretions will inevitably result in suboptimal ventilation
• Airway mucus hypersecretion can increase the risk of hospitalization and mortality