Loss of smell, known medically as anosmia, is an inability to perceive odors. It can be partial or complete and, while rarely the symptom of a serious condition, can still cause misery for those suffering from its effects. It is usually temporary—the result of a cold or upper respiratory infection—but sometimes may be permanent. It has recently been identified as one of the presenting symptoms in COVID-19 infections.
What Causes Loss of Smell?
Anosmia occurs when the sinuses become swollen and inflamed. The most common causes include colds, flu, allergies, sinusitis, nonallergic rhinitis and most recently COVID-19. Nasal obstructions such as polyps, tumors and other deformities can block the flow of air through the nose and lead to a loss of smell.
There are many other possible causes including Alzheimer’s disease, brain tumor, aneurysm, diabetes, cocaine use, chemical exposure, malnutrition, hormonal imbalances, medications, Parkinson’s disease, rhinoplasty, radiation therapy and old age, among others.
Anosmia is a prominent sign of SARS-CoV-2 infection. Patients with COVID-19 can present a sudden onset of anosmia without any other symptoms.
For most people, smell, taste and chemesthesis recover within weeks. It’s been reported 1 that 72% of people with COVID-19 who had olfactory dysfunction recovered their sense of smell after a month, as did 84% of people with taste dysfunction.
What Are the Symptoms of Loss of Smell?
Obviously, the telltale sign of anosmia is a loss of smell that cannot be traced to a cold or allergy. Some patients report a change in the way things smell. If the condition persists for longer than two weeks, you should consult a doctor.
How Is Loss of Smell Treated?
Treating anosmia depends on what causes it. If a cold or allergies are to blame, treatment is unnecessary; your sense of smell should return in a few days as symptoms improve. If a polyp or other growth is blocking your nasal passages, surgery may be necessary.
Loss of smell can’t always be treated effectively, particularly if it is the result of age. In these cases, it’s important to take extra precautions to ensure your safety. Make sure the batteries in your smoke detectors all function properly and change them often. Take care when eating leftovers; your sense of smell directly affects your ability to taste, and consuming spoiled food could cause serious health problems.
Smell Training for Loss of Smell
An effective way to treat loss of smell involves sniffing at least four different odors twice a day every day for several months. Smell training is based on the brain’s ability to reorganize itself to compensate for a change or injury. There are a variety of smell training kits — including different odors, like eucalyptus, lemon, rose, cinnamon, chocolate, coffee, lavender, honey, strawberry and thyme. You can make your own by purchasing different scented oils.
Call Dr. Stolovitzky at (404) 921-5474 for more information or to schedule an appointment.
 Reiter, E. R., Coelho, D. H., Kons, Z. A. & Costanzo, R. M. Am. J. Otolaryngol. 41, 102639 (2020).