Loss of smell is commonly known as anosmia. Anosmia may occur due to natural causes such as age. It may also occur due to a severe infection in the sinuses which may block the sense of smell temporarily. It may also occur due to severe nasal congestion of blockage caused due to excessive mucus deposited in the nasal passages. This could be caused by something as simple as a common cold. Seasonal or nasal allergies may also be responsible for the loss of you olfactory senses. On a more serious, though rare note, it could also be a signal of some sort of neurological disorder. This could mean that it may be an indicator of tumors, a severe trauma or injury to the head, or some sort of nervous disorder. Sometimes, strong medications could also alter or lose the sense of smell. This would also be a temporary side effect, unless the medication you are taking is permanent or long term.
There are some simple rules to follow if you have lost your sense of smell temporarily. You must avoid using nasal decongestants as much as you can. You must also make sure you have stringent safety measures such as smoke detectors installed in your home, since you may not be able to smell the smoke and it may be too late to save yourself by the time you feel it.
answered by G R