Nose blowing propels nasal fluid into the paranasal sinuses

Intranasal pressures were measured in adults during nose blowing, sneezing, and coughing and were used for fluid dynamic modeling. Sinus CT scans were performed after instillation of radiopaque contrast medium into the nasoph arynx followed by nose blowing, sneezing, and coughing. The mean (+/- SD) m aximal intranasal pressure was 66 (+/- 14) mm Hg during 35 nose blows, 4.6 (+/- 3.8) mm Hg during 13 sneezes, and 6.6 (+/- 3.8) mm Hg during 18 coughi ng bouts. A single nose blow can propel up to 1 mL of viscous fluid in the middle meatus into the maxillary sinus. Sneezing and coughing do not genera te sufficient pressure to propel viscous fluid into the sinus. Contrast med ium from the nasopharynx appeared in greater than or equal to 1 sinuses in 4 of 4 subjects after a nose blow but not after sneezing or coughing.