Is a sinus infection contagious?
Last updated September 3, 2026.
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.
What to do
- Watch the clock for contagion. The underlying cold is most spreadable in its first days, before sinuses hurt.
- Know the bacterial pattern. Double worsening - better then worse - plus facial pain suggests bacterial sinusitis, which is not contagious.
- Use standard respiratory hygiene. Handwashing and covering coughs protect the household from the triggering virus.
- Escalate the long course. Symptoms past 10 days without improvement, or severe one-sided pain, earn a visit.
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