The sense of smell is known as olfaction. Molecules released from smelly things travel into the nose and get trapped in the cilia-rich mucus in the upper part of the nasal cavity. This triggers a chemical and neurological chain reaction that ends in the brain receiving information about the smell.
Olfaction improves quality of life in ways that may not be immediately evident. In addition to experiencing pleasant fragrances such as flowers, mowed grass, and laundered clothes, smell contributes to humans’ sense of taste as well. Nasal conditions can cause food to taste bland and flat, causing people to lose interest in eating a balanced diet, thereby contributing to unhealthy weight loss, nutritional deficiencies, and depression. Additionally, our sense of smell alerts us to potential dangers such as smoke, natural gas, and rotten food.
Anosmia (an-OHZ-me-uh) or, loss of sense of smell, can have a variety of causes, some serious, some not. In many cases, anosmia is temporary, caused by a cold, flu, allergy, or sinus infection. When the loss of smell persists, however, it can be indicative of a more insidious illness or trauma. Exposure to toxic chemicals, injury to the nose or sinuses, nasal polyps, certain medications and medical treatments such as antidepressants and chemotherapy can all reduce or eliminate a person’s sense of smell, as can Alzheimer’s disease, multiple sclerosis, Parkinson’s disease, and certain types of hormonal and neurological abnormalities and diseases.
At the onset of anosmia, you may gradually notice that familiar things lack smell or food tastes differently. If you experience a dramatic lessening in your ability to smell that you can’t attribute to a cold, allergy, or other known illness that lasts for more than one week, you should let your ENT doctor know.