How to Fight Flu

Good night sleep. Not just long. Early evening sleep is better than long morning slumber.

Zinc acetate has been used in lozenges for treating the common cold.
Pooling the results of three high dose zinc acetate trials indicates
an average 42% reduction in the duration of colds:
https://en.wikipedia.org/wiki/Zinc_acetate

Vitamin C consumed in black currant, oranges, apples, carrots etc.

Sauna. Opens your nose and sinuses. Helps you to sleep better.

Hot drinks (tea, chocolate) with honey.

Salvia, use it like tea https://en.wikipedia.org/wiki/Salvia

Nasal irrigation https://en.wikipedia.org/wiki/Nasal_irrigation

Garlic, opens your nasal ways and contains all kinds of weird antimicrobial stuff (scientific term)

Chili, opens your nasal ways, antimicrobial

Low-intensity exercise, such as walking

Ginger. Can be used with food and drinks and as dried pieces. Opens nasal ways and reduces inflammation.

Bilberry soup, preferably hot