Anosmia: When Your Nose Doesn't Know
Anosmia is a lack or loss of the sense of smell. To learn more about this smell disorder, from causes and treatments to personal experiences, read on.
What is Anosmia?
Olfaction, or the sense of smell, is one of the five primary senses used for perception. Sight, hearing, touch, and taste round out the list.
Many people take their sense of smell for granted. Have you ever wondered what life would be like without the ability to smell your favorite food or fragrance?
Some people do not have to wonder. A smell disorder keeps them from recognizing or distinguishing scents. They were born without the ability to smell, or they lost it somewhere along the way.
There is a name for this condition. The medical community calls it anosmia (an-OHZ-me-uh). Depending on the cause, the condition can be temporary or permanent.
While anosmia may indicate an underlying medical condition, it is not necessarily serious. However, a lack of smell can sometimes trigger a loss of appetite, which can lead to excessive weight loss, malnutrition, or even depression.
The Anatomy of Smell
The sense of smell originates with the olfactory nerves in the brain. At the top of the nasal passages, and behind the eyes, is a small patch of neurons with hundreds of odor receptors.
Because these olfactory receptor neurons are out in the open, they come into contact with air. Tiny hair-like projections called cilia increase their surface area.
Fragrant products, or anything with scent, have odor molecules -- light, volatile chemicals that are released into the air through evaporation. Non-volatile solids, such as steel, have no scent because nothing can evaporate from them.
In order for someone to perceive smell, odor molecules must enter through the nose. As they bind to the cilia, they trigger nerve signals to the brain. A specific gene encodes each olfactory receptor. If this gene is damaged or missing, a person cannot detect specific odors.
Nerve damage, brain injury, and other medical conditions can also cause problems with smell. They usually cause a decrease or loss of smell. In some cases, however, odors are intensified, distorted, or hallucinated.
What Causes Anosmia?
Anosmia has many different causes. The common cold is the usual culprit, and it creates a temporary loss of smell. Influenza, sinus infection, chronic congestion, allergic reactions, and sneezing that is unrelated to allergies are other prevalent causes.
Anything that obstructs the nasal passages and blocks airflow can cause smell problems. Nasal polyps, tumors, and bony deformities inside the nose are common nasal obstructions. Most nasal blockages cause partial loss of smell.
The Anosmia Foundation is a nonprofit organization based in Canada. Founded in 2001, its goals include:
- To promote the acceptance of anosmia as a medical disability
- To maintain support for those who suffer from anosmia
- To expand the availability and accessibility of treatment
- To inform and educate the general public about anosmia
- To encourage anosmia awareness in the medical community
According to the American Academy of Neurology (AAN), nearly 14 million people over age 55 have smell disorders.
The AAN says anosmia may be an early indicator of certain neurological disorders like Alzheimer's disease, multiple sclerosis, and Parkinson's disease.
Brain surgery and damage caused by tumors and aneurysms often impact smell. Diabetes, hormone imbalances, zinc deficiencies, and cancer drugs are also linked to anosmia.
Congenital anosmia is a rare condition that causes a lifelong inability to smell from birth. It is often a symptom of Kallman syndrome.
Medical treatments help people with temporary anosmia recover their sense of smell. Antibiotics clear up bacterial infections that interfere with smell, and antihistamines are helpful for allergy related symptoms. The surgical removal of nasal polyps can clear blockages and improve smell.
Cigarette smoke is known to dull the senses, including smell. Kicking the habit may improve the problem. The proper use of nasal sprays and decongestants may prevent problems with smell perception,and zinc supplements are worth considering as a natural remedy.
Sometimes, the sense of smell returns spontaneously. Many people, however, live with anosmia throughout their lives. When a lack of smell is due to nasal inflammation or infection, it is usually temporary. People with olfactory nerve damage may never recover the sense of smell.
Congenital anosmia is hard to diagnose because it does not show up in medical tests. People with this condition must learn to live with the disorder because there is no cure or treatment.
Compared to blindness and hearing loss, anosmia is a benign condition. While it is usually not life altering, it has its dangers. An inability to perceive smell can hinder awareness of fire, smoke, gas leaks, spoiled food, and other warning signals. People must rely on their other four senses to alert them to danger.
My Life Without Smell
"Smell is a primal sense," says Bonnie Blodgett in Remembering Smell. Most people can smell before they can think. I was born with a weak sense of smell, so I never relied on it for taste, emotion, or memory.
When I talk about my problem, most people have no idea what I mean. It makes no sense to people who can experience smell. Have you even heard of anosmia before now? I was surprised to learn that it had a name when I researched the subject some years ago.
My family and friends have short term memory when it comes to my sense of smell. After all this time, they still forget. "Smell this," they say as they hand me a bar of soap, a plate of food, or a cologne counter sample.
Even in the midst of my protests, they tempt my nostrils. "See if you can smell this," they say. So I sniff. "You smell it now, right?" they ask. "Yes, I think I can smell it," I reply. "It's really nice." Sometimes, it is just easier to pretend.
There is a silver lining, however. It is my good fortune not to smell bad odors like dog breath, dead skunks, automobile exhaust, dirty laundry, or excessive sweat and body odor.
But I also miss out on many of life's pleasant scents, such as the smell of rain, fresh flowers, Christmas pine, baby powder, fragrant candles, kitchen aromas, and my husband's cologne. Such is my life without smell.
What About Taste?
My inability to smell scent makes me unaware of what I am missing. But I know what is not missing: my sense of taste.
"What about food? Can you taste anything?" is a common question for those with anosmia. Some people think they already know the answer. In fact, they are quick to inform anosmia sufferers that, "You can't taste food if you can't smell it."
This is simply not true -- for me and many others with my condition. Smell and taste are two different senses, and the inability to perceive them are two different conditions.
Ageusia describes a lack of taste sensation. It is a companion term to anosmia, but it is not always a companion condition. Many people assume that those with anosmia have ageusia too, because the sense of smell helps people taste the full flavor of foods.
While a lack of smell may impact taste, most people can still identify the four main taste sensations: sweet, salty, sour, and bitter. My taste buds can do this. I can also appreciate the nuances of cheese, chocolate, cola, and other flavors. I may not experience them the way most people do, but their flavors are pleasurable to me. Especially chocolate!
You may wonder if I can smell anything. My sense of smell is very weak, and I can rarely perceive a fragrance or odor. But it happens from time to time. Here are two examples.
Once, after an early morning rain, my brother and I crossed the lawn of his business campus. "What's wrong?" he asked when I stopped suddenly. "Nothing," I replied, "but I think I smell something and I want to enjoy it." My brother explained that it was the lingering scent of rain mingled with the fresh cut grass. What an amazing scent.
On another occasion, my husband and I were shopping for candles. I looked for the visually appealing ones, and he looked for the great-smelling ones. As he sampled the fragrances, I was drawn to a candle with a strong cinnamon scent. I had to bury my nose deep in the jar to smell it, but still. It was nice.
Because these moments are rare, I rarely think about my disorder. My husband alerts me to any bad smells at home, and he also selects my perfume and other fragrant products. Whenever a "new" scent surprises me, I consider it a blessing from God.
Were you born with anosmia, or did you lose your sense of smell somewhere along the way? Leave a comment and join the discussion. If you enjoyed this article, please share it with your social networks.
- Blodgett, Bonnie. (July 16, 2010) "Anosmia: The Quiet Killer." The Huffington Post. Retrieved October 25, 2011.
- Brynie, Faith. (December 1, 2010) "New Help for Anosmia Sufferers." Psychology Today. Retrieved October 25, 2011.
- Discovery. (n.d.) "How Does the Nose Work?" Discovery Fit and Health. Retrieved October 25, 2011.
- Dunkel, Tom. (December 14, 2003) "The Unknowing Nose." The Baltimore Sun. Retrieved October 26, 2011.
- Mayo Clinic. (February 8, 2011) "Loss of Smell: Anosmia." Mayo Foundation For Medical Education and Research. Retrieved October 25, 2011.
- NPR. (June 17, 2010). "Five Senses, Minus One: Living Without Smell." National Public Radio: Books. Retrieved February 23, 2014.
The information presented in this article is not intended as health or medical advice, nor is it a substitute for diagnosis or treatment by a qualified medical professional.
© 2011 Annette R. Smith