Wednesday, October 20, 2021
These days a sudden loss of taste and smell is a cause for alarm. Of course, the first thing that jumps to mind is the potential of having COVID-19.
The good news is that COVID-19 isn’t the only disease that can lead to a loss of taste and smell. Other potentially less serious issues could be the reason, too.
Other Viruses
Coronavirus is a family of viruses that can cause respiratory illnesses such as the common cold, or more severe conditions like COVID-19. Many of the illnesses caused by coronaviruses can lead to loss of taste or smell.
Dr. Melissa McBrien, a Beaumont otolaryngologist (ear, nose, and throat doctor), says, “Along with a COVID-19 infection, other viral infections, such as colds, can result in a loss of smell and taste. Sometimes this is just for the length of the cold when the nose is blocked, but other times the lack of smell can last weeks to months.”
While it’s still a good idea to get tested if you think you have COVID-19, the loss of taste and smell alone isn’t a cause for alarm.
Allergies or Sinus Infection
Even if you don’t usually experience a loss of taste and smell during the allergy season, this could be the cause of your trouble.
Too much stuff in your nose dampens your ability to taste and smell. The same problem appears with sinus infections.
Aging
To a certain extent, the senses of taste and smell naturally dull with age. If you are age 60 or older, you might notice that these senses don’t work as well as they used to.
Certain activities or issues can speed the loss of these senses as well. These include:
- smoking
- dental problems
- nose or sinus problems (nasal polyps or growths, allergies, etc.)
- head or facial trauma
- some types of medication
- Alzheimer’s or Parkinson’s disease
These types of loss of taste and smell tends to come on gradually, so you may not notice it right away.
Loss of Taste and Smell Treatment
How long does the loss of taste and smell last and is there anything you can do about it?
“While we used to think loss of smell was permanent if it lasted more than six months, we now know that it will often recover slowly over the years,” Dr. McBrien said. “Treatments such as smell training can be helpful in the recovery of this important sense.”
You may also be able to speed recovery by addressing the root cause. For example, your doctor may suggest steroid nasal sprays or drops to treat nasal polyps or sinusitis.
There are even some home remedies for this issue. These include smell training with pungent odors such as coffee or fresh ginger, placing drops of castor oil in your nose and using a saline rinse.
Keep in mind that working smoke and carbon monoxide detectors are essential in the homes of people who have lost their sense of smell. They won’t have the ability to detect these life-threatening situations as early as someone else.
Dr. McBrien says that if you’re concerned about new or worsening loss of taste and smell, your first step should be contacting your primary care doctor. If your diagnosis requires additional follow up, you may be referred to an ENT specialist.
Next Steps and Helpful Resources
- Which COVID-19 test is right for you?
- Learn more about the COVID-19 virus
If you’re having trouble detecting strong odors or scents, or you’re struggling to distinguish between different flavors when eating, you may be experiencing anosmia (loss of smell) or hyposmia (partial loss of smell).
Similarly, if you can’t taste flavorful foods, or you notice that some foods taste different or metallic, you may be experiencing ageusia (loss of taste) or hypogeusia (partial loss of taste).
Often, the loss of taste and smell go hand-in-hand, as there is a strong link between the two senses. Odor receptors in your nose and upper throat work together with the taste receptors on your tongue to create the experience of flavor. This is why when you have a stuffy nose, you may notice that foods don’t taste as flavorful.
The sudden loss of taste or smell can be a temporary symptom of common illnesses like the cold or flu, or a long-lasting symptom of a serious injury or chronic condition that disrupts your brain’s ability to process scent and flavor.
What Is Anosmia (Loss of Smell)?
Your sense of smell comes from olfactory sensory neurons, found inside your nasal tissue. Each of these neurons has an odor receptor—when odors are released around you, these receptors detect the smell and send a message to your brain, which interprets and identifies the scent. When any part of this process is interrupted, your sense of smell may be impaired.
This sensory process may be interrupted in three main ways:
- Blockages in the inner lining of the nose: These blockages can prevent smells from reaching your odor receptors.
- Obstructions to the nasal passages: Your odor receptors can’t send messages to the brain if your nasal passage is obstructed.
- Damage to the brain or nerves: An injury or other damage to your brain or nerves can impact your brain’s ability to interpret and identify smells.
If you are suffering from anosmia or hyposmia, you may notice that traditionally strong scents seem muted to you, or you can’t smell odors that others around you can easily detect.
You may also notice that your sense of taste is dulled or absent, or that you have trouble distinguishing between different flavors, because your odor receptors play a role in your ability to taste.
What Is Ageusia (Loss of Taste)?
When you taste something, you’re actually experiencing a two-step chemical reaction involving the mouth, throat, and nose. Your body combines the senses of smell and taste to process the flavor of foods and beverages.
When you consume food, your odor receptors can usually smell the substance before you even put it in your mouth. As you eat or drink, the substance mixes with saliva in your mouth, transporting the taste around the tongue and activating your taste buds. This then sends signals to your brain, and combining both smell and taste, your brain interprets the flavor.
People with ageusia (complete loss of taste) cannot taste sweet, salty, sour, or bitter flavors. People with hypogeusia (reduced sense of taste) can generally taste these flavors, but may not be able to distinguish easily between them. With either ageusia or hypogeusia, you may also experience a metallic sensation in your mouth.
What Causes Loss of Smell and Taste?
There are several factors that might contribute to your loss of smell.
Aging
One of the most common causes for a gradual reduction in smell and taste is aging. As many as 75% of people over the age of 80 have an impaired sense of smell. A diminished sense of taste is also quite common because after age 50, our taste buds start to lose their sensitivity and ability to regenerate.
Stuffy Nose
Any viral or bacterial infection that causes a stuffy or runny nose—such as a sinus infection (sinusitis), the common cold, or flu (influenza)—can block odor receptors, resulting in a temporary reduction of smell and taste. This is why food often tastes less flavorful when you have a cold.
When caused by an infection, hyposmia and hypogeusia are usually temporary symptoms; once the infection has cleared, the senses of smell and taste return.
Other causes that can produce a stuffy nose and temporarily and sporadically impact smell and taste include:
- Allergic reactions
- Hay fever (allergic rhinitis)
- Nonallergic rhinitis (chronic congestion or sneezing not related to allergies)
- Upper respiratory infections
- Smoking
Obstructions
Obstructions to the nasal passages can interrupt the process by which odor and taste receptors send messages to the brain. Your nasal passages may be obstructed due to:
- A deviated septum
- Traumatic brain injury (TBI)
- Tumors
- Abscesses such as nasal polyps
In many cases, the loss of taste and smell is temporary and will be recovered if the obstruction is removed. In more serious cases, damage to the nasal cavity or olfactory nerves due to a head injury or traumatic brain injury (TBI) can result in long term or permanent loss or reduction of smell and taste.
Other Causes
More extreme or sudden loss of taste and smell can be caused by other illnesses and conditions that impact the inner lining of the nose, the nasal passage, or the brain. An impaired sense of smell or taste can be a symptom of:
- Certain medications: Some antibiotics, antihistamines, high blood pressure medicines, intranasal zinc products, and nifedipine, have been known to have side effects including loss of smell. In these cases, stopping the medication will generally reverse the effect, although in severe cases, anosmia may become permanent.
- Coronavirus: Loss of taste and smell has also been identified as a potential symptom of coronavirus (COVID-19), which may or may not be accompanied by flu-like symptoms including fever, dry cough, muscle pain, and shortness of breath.
- Radiation therapy: Impaired smell and taste can also be a side effect of radiation therapy for patients undergoing cancer treatment.
- Diabetes: Studies suggest that people with diabetes may be more prone to impaired taste.
- Multiple sclerosis (MS): Because MS impacts the central nervous system, it can cause loss of smell. Some evidence suggests that loss of smell may be an indicator of the severity of this disease.
- Neurodegenerative diseases: People suffering from diseases like Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, or similar conditions may show extreme changes in their food preferences and struggle to identify flavors, indicating possible loss of taste buds and impact to sense of smell. Some researchers posit that decreased sense of smell could be an early indicator of Alzheimer’s or similar causes of neurodegeneration.
- Zinc deficiency: Zinc is an essential trace mineral that our bodies need to support immune system functions and cell regeneration. People who don’t get enough zinc through their diet may experience a diminished sense of taste or smell, among other symptoms.
Diagnosis and Testing
To test for anosmia or hyposmia, your doctor may hold a fragrant substance (such as soap or coffee) under your nostrils and ask you to identify the smell.
If this informal sniff test shows an impaired sense of smell, your doctor may then use a standardized smell test kit for a more complete assessment. The kit may include scratch-and-sniff scent samples that you’ll be asked to identify, or samples of a strongly scented chemical that your doctor will dilute in stages to find the threshold where you can no longer smell the substance.
If the loss of taste and smell is more severe and your doctor has ruled out viral and bacterial infections, your doctor may order an MRI or CT scan to look for any structural issues including a tumor, fracture, or abscess.
Treatment for Loss of Smell and Taste
The primary approach to treating loss of taste and smell is to treat the underlying cause of the issue. There is no direct cure for anosmia and ageusia, though in most cases, treating the cause will return all or part of your sense of smell and taste.
A stuffy or runny nose due to allergies or a viral infection (such as cold and flu) can be treated with over-the-counter medications including decongestants, antihistamines, or steroids to ease inflammation. Easing the stuffiness may help increase your sense of taste and smell in the short term.
Once the body has recovered from the cold or other infection, your senses of smell and taste will fully return. Bacterial sinusitis and throat infections are generally treated with antibiotics. If you are suffering from a sinus infection, treatment may also include steam inhalation to clear the nostrils and ease pressure.
For regular smokers, quitting the habit of smoking tobacco products can result in regaining a sense of taste.
If hyposmia or hypogeusia is the result of aging, a chronic condition, brain trauma, or another cause that permanently alters the senses, there is no treatment to fully regain these senses. In these cases, patients are encouraged to:
- Add more seasonings: Season your food with herbs, spices, vinegar, hot sauce, or other flavorings. Be open to trying new sauces and condiments—if your sense of taste has changed, you may enjoy flavors you didn’t before.
- Try new cuisines: Experiment with different cuisine styles, especially those that have traditionally strong flavors, such as Indian or Mexican cuisines.
- Eat hot foods: The temperature of food can affect our sense of taste. Studies have found that the hotter food is, the more intensely our taste buds react. When possible, heat your meals instead of eating them cold or at room temperature.
- Look for textures: Texture contributes to our enjoyment of food, so try different foods that are crispy, crunchy, or smooth, as this may engage your senses in fresh ways.
- Watch your salt and sugar intake: If you suffer from hyposmia and hypogeusia, you may be drawn to foods high in salt or sugar, as these flavors are often easier to taste. Be mindful not to overdo it with sweet or salty foods in your diet.
When to See a Doctor
If you are experiencing a diminished sense of smell or taste, take note of any recent health issues or changes in your routine, as well as any accompanying symptoms to determine how soon to speak with a doctor. You should see your doctor immediately if you have recently experienced a serious head injury, started a new medication, or are undergoing radiation therapy.
You should also see your doctor if you experience loss of taste or smell in conjunction with the following symptoms:
- Frequent memory loss and confusion
- Sudden difficulty performing otherwise routine tasks
- Challenges with cognitive functions such as speaking and writing
- A sore throat
- Postnasal drip
- Green or yellow nasal discharge
- A fever
- Sudden weight loss, either unexplained or due to difficulty eating
- Open sores or other wounds that won’t heal
If you are worried that you may have coronavirus, chat with a K Health doctor today.
How K Health Can Help
Did you know you can access online urgent care with K Health?
Check your symptoms, explore conditions and treatments, and if needed, text with a healthcare provider in minutes.
K Health’s AI-powered app is HIPAA compliant and is based on 20 years of clinical data.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.