[BrandoElFollito]

> in German, many people call a regular cold a flu here.

Intersting, in France we have the "flu-ish state" (un état grippal) when you have a seriuos cold.

Flu (grippe) is a real sickness, determined by the doctor or extrapolated from the context (everything around your head it, now it's your turn).

They are very distinct, though.