system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why does spicy food loosen your sinuses?

People always suggest chicken soup and spicy food whenever I'm feeling all stuffed up. Spicy food ALWAYS works. Why is this so?

Thanks Reddit!
gpt
Spicy food loosens your sinuses because your body reacts to the capsaicin in spicy food. 

Capsaicin acts on pain receptors in your mouth and triggers biological countermeasures designed to increase airflow and flush out irritants. You experience this reaction as runny nose, eye watering and an increase in salivation.