What Causes a Runny Nose? How Does a Runny Nose Start?

What Causes a Runny Nose? How Does a Runny Nose Start?

14 Aug 2018

Have you ever developed a runny nose and thought to yourself, “How does a runny nose start?” “What causes a runny nose?”

The simple answer to explaining runny nose causes is this: Before your nose starts running, bacteria, allergens, or a virus attacks and irritates your nose's lining. This seemingly innocuous event sets off a complex chain reaction within your body, leading to what we commonly experience as a runny nose. Let's dive deeper into the fascinating process behind the scenes of runny noses.

What Causes A Runny Nose? The Science Behind a Runny Nose

The Trigger: Irritation and Inflammation

Your nose is a sophisticated filter and defense system that works constantly to protect your respiratory system from harm. Anything that irritates inside the nose is a potential trigger for a runny nose. Changes in temperature, pollutants, and cold or dry air can all trigger a runny nose. And when foreign invaders like bacteria, allergens, or viruses enter your nose, your body's immune response kicks into high gear. The initial interaction between these irritants and your nose's sensitive lining triggers an inflammatory response.

Inflammation and Mucus Production

Inflammation is your body's way of triggering its defenses against potential threats. It involves increased blood flow to the affected area, bringing in white blood cells to combat the intruders. As part of this defense strategy, the cells lining your nasal passages start producing mucus at an accelerated rate.

The Clear and Runny Phase

The excess mucus that's produced initially is usually clear and runny. This transparent mucus serves as a frontline defense mechanism. It's your body's attempt to swiftly remove the germs or irritating substances that have managed to infiltrate your nasal passages. The runny consistency helps to wash away these intruders, and you might find yourself reaching for tissues more often during this stage.

Changing Colors: The Immune System in Action

As your immune system gets to work and starts combating the invaders, the nature of the battle changes. The influx of immune cells, enzymes, and other defense mechanisms can lead to the mucus changing color. The shift from clear to yellow or greenish mucus can indicate that your immune system is working to fight off the infection. These colors are often a sign of immune cell activity and the breakdown of cellular debris.

Patience and Recovery

While a runny nose can be uncomfortable, it's important to recognize that it's a sign that your body's defense mechanisms are working as they should be. Your immune system's efforts are focused on eliminating the threat, and the increased mucus production is a part of this process. Staying hydrated, getting enough rest, and providing your body with the nutrients it needs can help support your immune system's fight against the invaders.

Now You Know How Runny Noses Start

What Causes A Runny Nose? The Science Behind a Runny Nose

In conclusion, a runny nose is your body's response to irritants and invaders. The initial irritation triggers inflammation and increased mucus production, leading to the characteristic runny nose. As your immune system goes to work, the color and consistency of the mucus might change, reflecting the ongoing battle within. So the next time you find yourself reaching for a tissue, remember that it's a sign of your body's remarkable defense system in action.

References
  1. Mayo Clinic, Runny nose
  2. Medical News Today, Everything you need to know about inflammation
  3. Cleveland Clinic, Rhinorrhea (Runny Nose)
  4. Verywell Health, Decoding Mucus Color: Yellow, Green, Brown, and More