Smell and taste disorders are a group of conditions that involve altered smell and taste or loss of smell and taste.
Common disorders of smell and taste include:
Other disorders may cause pleasant odours to smell bad or pleasant tastes to no longer be enjoyable. Often, these disorders are associated with other conditions. For example, dysgeusia is commonly associated with pregnancy. Another relevant example is the loss of taste that accompanied early cases of the SARS-CoV-2 virus (coronavirus).
Common conditions accompanying smell and taste disorders include Parkinson’s, Alzheimer’s, multiple sclerosis, high blood pressure, bad nutrition, diabetes, and obesity.
There is a wide range of symptoms associated with smell and taste disorders. These include not being able to smell or taste anything, a reduced ability to smell and taste, and an unusual perception of what you’re tasting or smelling. This can include tasting all foods as metallic, sour, bitter, or sweet or tasting and smelling foods that are usually enjoyable as disgusting.
Causes of smell and taste disorders include nasal polyps, respiratory illness and allergies, hormonal changes like those experienced during pregnancy, an injury to the head, poor dental health, certain medication or chemical exposure, radiation therapy for cancer around the head and neck, snorting drugs through the nose, and cigarette smoking.
Risk factors for smell and taste disorders include being Black, drinking a lot of alcohol consistently over one’s lifetime, age, being a man, and having cardiovascular disease.
A doctor will take a medical history and do a comprehensive physical exam to diagnose a smell or taste disorder. You may be referred to an ear, nose, and throat specialist. A specialist can administer certain diagnostic tests, such as measuring the lowest strength of a smell you can recognize, comparing tastes and smells, sip, spit, and rinse tests, and scratch and sniff tests.
During a sip, spit, and rinse test, an individual tests various flavours like grape juice, coffee, and soy sauce. This allows doctors to measure how intensely they experience the flavour based on bitterness, sweetness, sourness, saltiness, or umami.
A scratch and sniff test simply asks participants to identify various odours.
Complications of smell and taste disorders include decreased quality of life, malnutrition, and a weakened ability to detect harmful odours like fire, poisonous fumes, or spoiled food.
Smell and taste disorders are treated based on age, medical history, tolerance for specific therapies, and if the condition is thought to be permanent or if it will pass.
Treatments may include:
Working closely with your medical provider, you can regain lost smell and taste.