3. Nasal Congestion
The blockage of upper respiratory passageways, such as the nose, is mainly caused by our body’s immune response to infection. Flu infections are contracted when a person comes into contact with the air-borne viruses released by sick individuals. These aerosols find their way into the respiratory airways which serve as the viruses’ entry point, from which they spread into a patient’s system. It is because of this that the body’s responses activate, causing a swelling in the membranes of the nose due to an increase in blood flow which allows more of the body’s defenses to reach the infection.