system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: my girlfriend gets super stuffed up when we sleep with the fan on. Why?
gpt
Allergy suffer and frequent traveller. It's because allergens rest on things. Dust, mold, pollen, hair, and others will rest until disturbed. Turn on the fan and the airflow will pick it up and into your sinus. Add in it will bteak your bubble of humidity and push dryer air to you, you get stuffy. Get a filter or humidifier.