Hello, I can understand your concern and can give you a suggestion regarding your problem. Have you recently been through an extraction of the upper molar tooth on the left side? Or have you had a check up by the dentist regarding infections in the oral cavity recently? The reason of my this suggestion is that sometimes the roots of the upper molar are situated in the maxillary sinus. In such cases, when the tooth is extracted or is decayed with extensive infection in the roots area, the maxillary sinus lining gets infected and an opening forms between mouth and sinus called oroantral fistula. In such cases, whatever is put in mouth, part of it enters the sinus and comes out through nose. I would advise you to visit your dentist for physical examination of the area and x-ray of the upper left molar to examine the roots area of the tooth along with sinus lining. If there is indeed a fistula formed, a opinion of maxillofacial surgeon might be required to treat the infection and close the opening. I hope this information helps you. Thank you for choosing HCM. Let me know if you have follow up questions. Best, Dr. Viraj Shah