system
Given the following post, respond as if you're commenting on Reddit:
human
Why does blowing my nose (when it's closed for allergies or a cold) not free it?

I have pollen allergy.. Why is blowing my nose useless if I feel it's blocked?
gpt
Because it's not usually just obstructed by mucus or any other foreign body. 

When you're all stuffed up, it's usually the membranes of the nasal passage way becoming swollen from inflammed blood vessels. This just means the hole you're trying to breath through has got significantly smaller.