9 Reasons You Might Be Losing Your Sense of Smell

Medically Reviewed By William C. Lloyd III, MD, FACS
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Is your nose not noticing your favorite fragrances? Does food not taste as good as it used to? Does the aroma of freshly brewed coffee no longer wake you up in the morning? Then you may be experiencing anosmia, the loss of your sense of smell.

Individuals who have tested positive for COVID-19 have reported losing their sense of taste or smell as they developed symptoms. The U.S. Centers for Disease Control and Prevention have identified anosmia as a symptom of COVID-19. Doctors in China, South Korea, Italy and Germany have reported high rates of loss of smell or taste in infected patients.

But anosmia can have several "typical" causes, and this loss can sneak up on you more slowly than hearing or vision loss. It also can have a big impact on your health and safety. Besides alerting you to pleasant odors, your nose can signal danger like a gas leak, spoiled food or fire. Because your sense of smell is controlled by sensors in the nose that connect to your brain, the loss of smell can be triggered by a variety of conditions that range from temporary to permanent. Here are nine reasons your nose might be malfunctioning.

1. Sinus and Nasal Problems

One of the most common reasons for temporarily losing your sense of smell is, you guessed it, the common cold. When your sinuses swell or get clogged with mucus they block the odor receptors in your nasal tissue. Fortunately, this is usually a partial, temporary condition easily remedied once your cold is over. Chronic sinus infections or severe allergies can sometimes lead to ongoing anosmia. Other nasal obstructions like polyps are typically temporary since they can be removed.

2. Smoking

In addition to smelling bad themselves, cigarettes also mess with your sense of smell. Smoking is a form of pollution, and regular exposure can limit your ability to smell, as well as taste. The good news is once you quit smoking or reduce your exposure to second-hand smoke, your sense of smell usually returns.

3. Nervous System Disorders

Since the nose is so well connected to the brain, a loss of smell can be an early indicator that something unusual is going on with your nervous system. A recent study published in JAMA Neurology reports that older adults who did poorly on smell tests were 2.2 times more likely to have memory problems that may evolve into Alzheimer’s disease. Though there wasn’t a direct cause and effect between anosmia and neurodegenerative disease, if you’re experiencing a loss of smell, it’s worth a conversation with your doctor.

4. Head Injury

Again, the brain’s connection to smell can come into play after a head injury. From concussions to brain surgery, any type of head trauma might affect your smell when olfactory nerves are cut, blocked or damaged. Depending on the severity of the injury, this loss could be permanent or temporary. When your sense of smell starts to return, it’s usually a sign your brain and nerves are healing.

5. Medications

Have you noticed anosmia listed in your medication’s list of side effects? Certain medications like antibiotics, antihypertensives, and antihistamines can sometimes cause a temporary loss of smell, but your nose should be back in business once you quit taking the medicine.

6. Aging

Like vision and hearing, your sense of smell gets less sharp as you age. After age 60, you have a greater chance of losing your smell, which can also alter your sense of taste. This combination contributes to progressive weight loss among the elderly.

7. Radiation Treatment

Patients who receive radiation treatment for head and neck cancers typically experience problems with their sense of smell as a side effect. The loss of smell can be temporary or become permanent as treatment continues.

8. Chemicals

Exposure to harsh chemicals, like insecticides or solvents that can burn the inside of the nose, may permanently damage your nasal tissue and odor sensors. Frequent culprits include: methacrylate vapors, ammonia, benzene, cadmium dust, chromate, formaldehyde, hydrogen sulfide, nickel dust, and sulfuric acid. To protect yourself, wear a respirator device that covers your nose when handling any strong-smelling chemicals at home or at work. Disposable masks provide inadequate protection.

9. Genetics

Some people are simply born with little or no sense of smell. This is known as congenital anosmia, and it often occurs alone or it can accompany other genetic disorders. The good news is loss of smell doesn’t always affect taste, so you can still enjoy those freshly baked chocolate chip cookies even if you’ve never smelled them.

Because the loss of smell can be caused by so many different conditions, many of which are brain related, it’s important to be checked by your doctor if you ever notice your nose not working as well as it used to. There could be a bigger reason for your problem than just the sniffles, or you may find a treatment to restore or improve your sense of smell.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Aug 6
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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