This problem may be aggravated by the taste or smell of food too. But these may not be the only factors. If you are exposed to odors such as perfumes, scented candles, paint fumes, smoke, diesel exhaust, etc. there are chances that you may suffer from a runny nose. Other factors can also include hormonal changes, especially during menstruation, changes in the air temperature, like when you are exposed to air conditioning, humidity, emotional stress and certain common medications.