system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does our body produce snot/congestion when we have a cold?
gpt
**Long Answer:**  When you have a cold, the viruses trigger a form of your body's defenses called histamines. These histamines are meant to make it easier for white blood cells to pass through blood vessels and capillaries to combat germs/pathogens (they're pretty much clearing a path for the body's "army" to combat the invaders). This has the side effect of inflaming your nasal passages and producing more, thinner mucus.

**Simplified ELI5 Answer:** Basically, your body tries to defend itself from invaders, but in the process causes collateral damage, leading to your once dry nose and countless tissues being filled with mucus.