Nasal Shield Sinus DropSinus Drops for Quick Relief Solution Sinusitis, commonly referred to as a sinus infection, is an inflammation or swelling of the tissue lining the sinuses. It can be caused by viruses, bacteria, fungi, allergies, or structural issues such as nasal polyps or deviated septum. A blocked nose can be attributed to various reasons such as nasal polyps, deviated nasal septum, sinusitis, common cold, adenoid hypertrophy, nasal allergies, hypertrophic