Nasal blockage is very common. There are several reasons why it may be hard for you to breathe out your nose and there’s a bit of a difference between adults and kids. In adults, a deviated septum, allergies, sinus infection, and polyps are the most common reasons. Other reasons include: 1. Turbinate enlargement 2. Septal perforation 3. Nasal dryness 4. Cold/infection 5. Nasal or nasopharyngeal tumor/growth 6. Congenital deformity 7. Trauma In children, one of the most common reasons is enlarged