Can The Flu Cause A Sinus Infection?

Can the flu lead to a sinus infection...yes and no. No the flu can't cause a sinus infection. Sinus infections are caused by bacteria, virus, or fungus. That said having a strong immune system and good overall health is what is going to prevent a sinus infection. If your immune system is already weakened your at more risk to get a sinus infection. Also if your sinuses are all clogged up it's easier for bacteria, fungi, viruses to get stuck in there.