One side of your nose is usually more blocked than the other
You have trouble breathing through one or both nostrils
You often feel congested even without a cold or allergies
You snore loudly
You breathe through your mouth, especially at night
You get frequent nosebleeds
You have repeated sinus infections
You feel pressure or pain in your face
You notice one nostril seems smaller than the other
You have a whistling sound when breathing through your nose
Your symptoms are worse on one side
A doctor confirms it with a nasal exam or imaging