The autonomic nervous system (ANS) regulates the functions of our internal organs (the viscera) such as the heart, stomach and intestines.
The flu is contagious a day before and five days to a week after its onset. Young children, people over 65, those with compromised immune systems, and people with a terminal illness are at risk of death from the flu.
The contagious period for the flu is similar. A study found youâre most contagious during a 2-3 day period after the on-set of symptoms. But just like a cold, you can still spread influenza during the entire time youâre sick - anywhere between 2 and 10 days. Itâs possible to infect others one day before you feel any symptoms like a high fever, muscle aches, sinus problems and stomach issues.