Sense of smell plays a very important in our daily lives. Besides the olfactory memories, the smell can alert us to the smoke of a fire , dangerous fumes, or spoiled food. The sense of test is related to smell. Loss of smell can result from a physical blockage of the nose like deviated nasal septum, allergies or nasal polyps. Some metabolic disorders , damage to the olfactory nerve by viral infections, trauma to the head or growth can cause also cause loss of smell.