Taste and Smell Disorders

IMAGE Imagine not being able to smell cinnamon rolls, freshly coffee, or flowers. How about not being able to taste the foods you like. This is a daily challenge for people who have lost part or all or part their senses of taste and smell.
Disorders that cause a loss of taste and smell can be very frustrating. They can also be dangerous. Impaired senses may delay your ability to identify harmful substances like smoke or toxic fumes. A lack of smell and taste may also affect the appetite. This can easily lead to weight loss and even malnutrition.

The Taste-Smell Link

Taste and smell are closely linked. Both sensations combine to play a role in how you recognize and appreciate flavors.
Taste buds on your tongue sense 5 basic taste sensations:
  • Sweet
  • Sour
  • Bitter
  • Salty
  • Umami (the savory taste)
Smell allows you to recognize many other, more complex flavors. For example, if you held your nose while eating some lemon pudding, you would have a hard time naming the lemon flavor. You would, however, be able to know it is sweet or bitter.
If you’re having a hard time tasting your food, you may have a problem with your taste buds. Though it is more likely that the problem is with your sense of smell.

What Are Taste and Smell Disorders?

People with taste disorders may have one or more of the following:
  • Phantom taste perceptions (tasting something that isn’t there)
  • Reduced ability to taste the 5 basic taste sensations
  • A distorted sense of taste
A total loss of taste is possible but rare. What someone may think is loss of taste is usually a loss of smell.
People with smell disorders may have:
  • Loss in the ability to smell
  • Changes in their sense of smell
  • Hyposmia—a decreased ability to detect odors
  • Anosmia—can’t detect odors at all
  • Familiar odors may be distorted—an odor that usually smells pleasant may smell foul to them or they may perceive an odor that isn’t present

Causes of Taste and Smell Disorders

A small number of people are born with taste disorders. Most taste and smell disorders are caused by:
  • Upper respiratory infections, such as a cold or the flu
  • Breathing allergies
  • Nasal congestion from irritants, such as pollutants and cigarette smoke
  • Sinus infections
  • Nasal polyps—noncancerous growths in the nose and sinuses
  • Head injuries
  • Bell's Palsy—infection of the facial nerves
  • Exposure to certain chemicals, such as insecticides and solvents
  • Certain medications, such as antibiotics and blood pressure pills
  • Radiation treatments for head and neck cancers
  • Increased age, which can make sense of smell less accurate (generally occurs after age 60)
  • A number of other health problems, including:
  • Oral health problems, such as gum disease
  • Some surgeries, such as third molar extraction and middle ear surgery
  • Smoking
  • Cocaine use

Diagnosis and Treatment of Taste and Smell Disorders

Smell disorders may be diagnosed with “scratch and sniff” tests. They will test how easily you can name common odors. To look for potential causes, the nose and sinuses may examined with:
  • Endoscope—a camera that can look inside the nose
  • CT scans—to look at the sinuses, nerves in the nose, or lesions in the brain
Taste disorders may be diagnosed through a chemical test. The lowest levels of chemical will be given to test how well someone can detect a taste sensation. Tests will also include a taste comparison, and tests that measure intensity.
Some taste and smell disorders can be treated, but others cannot. Depending on the cause, treatment may include:
  • Treating an underlying medical condition
  • Changing or adjusting medicines
  • Surgery—to remove obstructions in the nose, such as polyps
Most people will recover their sensations when the related illness or allergy has passed.

If You Have Lost Taste or Smell

If you have lost taste or smell, you should see your doctor. It may resolve in time, once the cause has passed or is treated. Smoking can also dull your sense of taste and smell. Quitting can improve your senses.
If the loss is permanent, some steps may make eating more enjoyable:
  • Eat warm food
  • Choose flavor-enhanced foods or those with natural strong flavor
  • Avoid add excess salt or sugar to flavor your foods
  • Intensify flavor with herbs
  • Make food more visually appealing
  • Try mixing food textures

RESOURCES

Asthma and Allergy Foundation of America  http://www.aafa.org 
Taste and Smell Clinic at the University of Connecticut Health Center  http://uconntasteandsmell.uchc.edu 

CANADIAN RESOURCES

Canadian Society of Otolaryngology—Head and Neck Surgery  http://www.entcanada.org 

References

Bromely S. Smell and taste disorders: a primary care approach. Am Fam Physician. 2000;61(2):427-436. Available at: http://www.aafp.org/afp/2000/0115/p427.html. Accessed http://www.aafp.org/afp/2000/0115/p427.html.
Smell & taste. American Academy of Otolaryngology–Head and Neck Surgery website. Available at: http://www.entnet.org/content/smell-taste. Accessed May 17, 2016.
Disorders of smell and taste. American Rhinologic Society website. Available at: http://care.american-rhinologic.org/disorders%5Fof%5Fsmell%5Ftaste. Accessed May 17, 2016.

Revision Information

Article written by Scholten A