Are nosebleeds common when you have a sinus infection?

Yes: Anything that irritates your nasal membranes or causes excess dryness can cause nosebleeds. Colds, sinus infections, allergies, cold dry air, nasal polyps, and sniffing or inhaling irritating substances into the nose can all cause nose bleeds. Very high blood pressure can also cause nosebleeds. So can a low platelet count or other blood clotting problem.