Two Common Causes: Why You Can't Breathe Through Your Nose The two most common reasons people have trouble breathing through their nose are chronic sinusitis and nasal obstruction. Sinusitis is a recurring condition that results in congestion and infection in the sinus cavities.
How can I breathe better through my nose?
Take a hot shower before bed, or sit in the bathroom with the hot shower running. The steam will help open your sinuses. It'll also help drain the mucus so you can breathe easier through your nose. You'll sleep better in no time.