Everyone who has suffered from a case of the common cold is familiar with the unpleasant side effects of a snotty nose and coughing up phlegm. But even though we know these symptoms occur when we catch a cold, most of us aren't sure why. In fact, most people aren't even aware that while mucous can be annoying during a viral infection, it actually plays an important role in our bodies. Read on to learn more about the general purpose of mucous, why production of it increases drastically after exposure to the cold virus, and what you can do to help alleviate symptoms.

Mucous come from the aptly named mucous-membranes, which are made up of a continuous lining of cells that serve to protect any body cavity that comes into contact with the external environment, such as our GI tract, respiratory system, and reproductive tracts. Specialized goblet cells and other cells residing in the membranes of the respiratory system produce mucous. Contrary to what some may think, mucous is actually produced in healthy individuals as well, and serves to protect respiratory tissues from drying out, since specialized proteins called mucins can absorb enormous amounts of water. Other proteins in mucous contain antibodies and enzymes to help fight off pathogens, and mucous also functions to help trap any foreign particles that end up in the lungs. Also, mucous helps moisten the air that we breathe.

Having normal quantities of mucous might be all well and good, but why does mucous production increase so drastically when you have a cold? Well, it's simple. When your airways get inflamed and infected due to the cold virus or allergies, mucous production increases to help remove pathogens and the foreign particles. Once this happens, voila! You've acquired a runny nose. Also, when the body's immune system starts the inflammation process in order to fight off pathogens or allergens, it also triggers a rise in mucous production. So, that annoying rise in mucous secretions is actually a normal byproduct of your immune system at work.

The increased production of mucous that accompanies a cold is not bad, in and of itself. However, the associated symptoms, including sneezing, sore throat, congestion, and coughing, can be annoying. Also, coughing, sneezing, and runny noses are a sure-fire way to spread the virus to others. And, if mucous thickens and gets trapped in the sinus passages, an infection can start. Therefore, cold sufferers may want to consider the use of decongestants to help alleviate symptoms during times of increased mucuous.