Nasal Congestion, Stuffy Nose, Allergic Rhinitis Nasal Congestion, Stuffy Nose, Allergic Rhinitis Understanding Nasal Congestion and Its Causes Nasal congestion, also known as a stuffy nose, is a common condition that can be caused by various factors. It occurs when the tissues lining the nasal passages become swollen and inflamed, leading to a blocked or stuffy feeling. This can make it difficult to breathe through the nose and may also be accompanied by other symptoms such as a runny nose, sneezing, and itching. One of the main causes