What is mucus?

Mucus and phlegm are produced by multiple tissues in the body to help protect from infection and prevent internal tissues from dehydrating.

When we breathe in, allergens, viruses, dust and other debris become trapped in the mucus or phlegm so that they can then be removed. Mucus also contains antibodies and enzymes that help fight off infections.

In healthy individuals’ mucus has a low viscosity (is thin) and is easily cleared from the lungs. When we become ill, excess mucus is produced which can become thicker and stickier than normal (has a higher viscosity) and can be harder to clear from the airways.

Thickened mucus and excess mucus production cause many unpleasant symptoms including:

  • Nasal congestion,
  • Sinus Pressure
  • Cough

The colour and consistency of mucus and phlegm can offer a clue as to what is happening in the body. Normal, healthy mucus is typically thin and clear while mucus that is white or yellow/green may indicate there is an infection.