Where Does All That Snot Come From During a Cold?

[DaveC426913]

What does yellow mean?

Same thing. Bacterial.

 

[DaveC426913]

A rule of thumb- if your mucus is cloudy, you have a bacterial infection. If it's clear, you have a viral infection. This is based on the size of the bug (light scattering).

Really? Huh. I'd always assumed the green/yellow was the carcasses of white blood cells.

 

[Moonbear]

The green/yellow thing I know applies to sputum (what you cough up and spit out coming up from your lungs), but I'm not so sure it applies to nasal mucus (what comes out when you blow your nose). Every time I've ever had a cold, it starts out clear and runny, and as I start to get better and the mucus isn't produced so copiously, it thickens and gets yellowish just before finally going away (that's yellowish and cloudy, not green...green is probably still a sign of bacterial infection). Now you guys are going to make me spend my lunch hour looking up references on snot...thanks.