Your mouth, nose, throat, sinuses and lungs are lined with mucus membranes. These membranes contain mucus glands that produce - surprise - mucus.
Mucus-producing membranes line specific passages in your body, like the respiratory and digestive tracts, for protection and support.
Mucus is a mixture of water, sugars and proteins (and other things that have long, scientific names). But even though this slippery, gooey liquid is far from glamorous, it plays an important role in your health.
The mucus that's produced in your respiratory tract has 3 important jobs:
- MUCUS PROTECTS. Mucus moistens and warms inhaled air and keeps the mucus membrane cells and the little hairs called "cilia" lubricated. These little hairs line the top layer of mucus membrane cells. Cilia helps to remove inhaled particles that have gotten trapped by the mucus layer covering the cilia. They need to stay moist to do their job.
- MUCUS ACTS AS A BARRIER. Mucus traps inhaled particles (like dust, allergens, bacteria, or viruses) and keeps them from getting deeper into your lungs. Mucus also keeps them from invading the cells lining your airway and entering your system. The cilia transport the mucus layer toward your throat, where it could either get spit out or swallowed.
- MUCUS DEFENDS YOUR BODY. Mucus contains antibodies, enzymes, and proteins that work to help get rid of whatever's in the air you've inhaled that could make you sick.
But sometimes, the mucus layer in your airways lets something slip by or is overwhelmed by the amount of particles inhaled. This could be bacteria, a virus that's getting passed around, or an allergen (like pollen) that will aggravate your respiratory tract.
One of the ways your body might react to an irritant or an infection is by producing more mucus. Your mucus may get thicker and change colour, too. Just one way your body attacks the thing that’s making you sick.