Nasal congestion is a condition in which the nasal passage is blocked due to inflammation of the blood vessels in your nose. This is also known as nasal blockage, nasal obstruction, blocked nose, stuffy nose and stuffed up nose. In infants this can be a life threatening condition because newborn infants often like to breath through their nose, and as such begin to have trouble breathing when they get congested. It can also prevent breathing while breastfeeding or can cause distress. Nasal congestion in older adolescents and adults is really just an annoyance however.
Nasal congestion is caused by any sort of irritation in the nose. The main culprits include influenza (the flu), sinus infections, nasal infections, allergies (mainly airborne allergies), nasal polyps. It has also been shown to be correlated with acid re flux. and while it is not caused directly by acid re flux, a lot of the things that cause it also can lead to acid re flux.
The main way to treat nasal congestion is with anti-inflammatory. But depending on the cause of the congestion they might bypass the congestion and just treat the cause. especially if it is something like influenza. Other treatments would vary based on the cause.