Mucus is naturally produced by the lungs to act as a protective lining.

It acts like fly paper. Inhaled dust particles and micro-organisms stick to mucus and are transported to the back of throat where they are swallowed.

  • In normal conditions, 30-100 ml of mucus is produced per day. This is similar to the volume of an eggcup.
  • During times of infection, mucus production can increase to 200 – 300 ml per day.
  • Mucus clears itself at a rate of 5-20mm a minute through the lungs.
  • The whole lung system is cleared and renewed every 24 hours.
  • Mucus is less easily cleared from the smaller bronchioles of lungs. This is where damage to airways is often found.
  • Lack of mucus clearance leads to stagnation and build up of secretions. This leads to chest infections.

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