Nasal congestion can be caused by anything that irritates or inflames the nasal tissues. Infections — such as colds, influenza or sinusitis — allergies and various irritants, such as tobacco smoke, may all cause a runny nose. Some people have a chronically runny nose for no apparent reason — a condition called nonallergic rhinitis ... Less commonly, nasal congestion can be caused by polyps or a tumor... Consult Ent surgeon for further evaluation and treatment...