No - you cannot catch a sinus infection; it is inflammation trapped inside your own sinus cavities.
But viruses cause most sinus infections per the CDC, and the cold virus that triggered yours is contagious - which is why household members often fall ill right after your sinuses started. You shared the virus, not the sinusitis. The bacterial sinus infection that follows a week into a cold is not contagious at all.
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Common questions
Is a sinus infection contagious?
The sinus infection itself, no - sinusitis is inflammation and infection trapped inside your own sinus cavities, and you cannot pass the condition to someone else. But the timing that makes people ask this question is real: viruses cause most sinus infections per the CDC, usually a common cold that swells the sinus passages shut and lets germs multiply - and that cold virus is contagious, spreading to household members in the days before your sinuses ever hurt. So when your partner gets sick right after your sinus infection started, you shared the virus, not the sinusitis. The bacterial sinus infection that sometimes follows a week or more into a cold - the one with the double-worsening pattern, thick discolored discharge, and facial pain - is not contagious at all; it is your own flora overgrowing in blocked passages. Contagion etiquette therefore tracks the cold, not the sinus infection: the first days of the underlying illness are when you can give it away. Pymander, a free AI doctor available 24/7 by text, can help you tell a cold from a sinus infection.