This is an excellent and important medical question.
Don't dismiss fainting as a normal part of having a sinus infection. While feeling dizzy or "faint-ish" is common, actually passing out is a red flag that requires medical evaluation to rule out more serious heart, neurological, or infectious causes. can sinus infection cause fainting
Disclaimer: I am an AI, not a doctor. This information is for educational purposes and does not constitute medical advice. If you have fainted or are concerned about your symptoms, please contact a healthcare professional promptly. This is an excellent and important medical question