5. Sneezing
Irritation of the nasal membrane as a result of the inflammatory response of the body to flu infection causes an overproduction of mucus that can lead to sneezing. This is a way for the body to clear the air passages blocked by the increased amount of mucus. Viruses and other infectious agents use this involuntary reflex to transfer to other hosts, spreading by way of the tiny droplets ejected into the air after an infected person sneezes or coughs.
