Hello, my name is Dr.Dorina Gurabardhi. I understand your concern. The altered sense of smell can be caused by many reasons such as: -nasal allergies -influenza -colds -hay fever Other conditions that can cause impaired smell include: -malnutrition -nasal tumors or surgeries -head injuries -sinusitis (sinus infection) -radiation therapy -viral upper respiratory infections -hormonal disturbances -nasal decongestant use -Certain prescription medications, like antibiotics and high blood pressure medications, can also alter your sense of taste or smell. A detailed visit to an otorinolaringologyst is needed to determine the cause and than proceed with the treatment. Hope my answer was helpful, if you have any other questions I ll be glad to help, thanks!