What Causes Loss of Taste?

From exposures to nerve issues to COVID-19

Woman looking unhappy as she looks at a bowl of sliced fruit

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Loss of taste may be caused by many things, including illness, taste disorders, side effects of medications, aging, and other health-related conditions. For example, if you suddenly can't taste anything and have a cold or allergies that are dulling your sense of smell, that may be to blame.

However, if the cause is unclear and lasts more than a few days, it's best to see a healthcare provider to identify what is going on.

This article explains how your sense of taste works, what causes loss of taste, and treatment.

The Centers for Disease Control and Prevention says the loss of taste or smell may be a sign of COVID-19 infection. If you suspect you or a loved one may be sick, contact your healthcare provider. Learn more about COVID-19, including how it's diagnosed and answers to common questions you may have.

How Your Sense of Taste Works

Your sense of taste is related to a combination of two different specialized cells, called olfactory and gustatory cells.

Olfactory cells are specialized cells that are high up in your nose. They connect to nerves that communicate with your brain. The second specialized cell, gustatory, are clustered in your mouth (particularly your tongue) and in your throat.

As you smell and chew your food, aroma is generated. This activates your sense of smell, while the food mixed with saliva activates your taste senses.

It's commonly assumed that different taste buds are clustered in certain sections of the tongue, but that's not entirely true. While there are different taste buds that respond differently to the foods you eat, they are not clustered in separate areas of the tongue.

All of your taste buds will react to all the different types of taste, but in varying degrees. 

There are five different taste buds scattered throughout your mouth and throat that contribute to the overall taste of the food you eat. These taste groups are:

  • Sweet
  • Sour
  • Bitter
  • Salty
  • Umami (savory - associated with chicken broth, Chinese food, meats, and cheeses)

With five tastes differing in degree of intensity based on the taste buds, in combination with smell and "mouth feel" touch of consistency and temperature, the experiences of taste can vary greatly.

If you've ever had a cold or congestion and felt that your food tastes different, that loss of taste is related to your loss of smell.

How Common Is Losing Your Sense of Taste?

Most people who visit their healthcare provider because they can't taste anything actually end up with an issue with their sense of smell. Every year, there are about 200,000 healthcare provider visits with complaints of a loss of taste.

However, it is estimated that while not everyone seeks medical attention when they lose their sense of taste, about 15 out of 100 adults experience problems with this sense.

Why You Can't Taste Anything (or Some Things)

The most common of four types of loss of taste is phantom taste perception, or phantogeusia. This is a sensation of a metallic or bitter taste in your mouth while there is not actually any food or scent to generate this sensation.

All four types of taste disorders include:

  • Phantogeusia: phantom taste perception
  • Hypogeusia: decreased sensation of taste
  • Dysgeusia: confusing the different tastes
  • Ageusia: complete loss of taste (rare)

Temporary or Permanent Loss of Taste

Some causes of taste loss, such as a cold or a medication-related change, are temporary. That's usually true of taste loss related to COVID-19 too. Other conditions, such as a chronic illness like Parkinson’s disease, may lead to a permanent change. Ageusia, a complete loss of taste, is rare.

In addition to taste disorders, there are a number of causes that affect your sense of taste. They include:

  • Medications (some antibiotics, antihistamines, and the cold remedy Zicam)
  • Nerve or brain disorders (stroke, traumatic brain injury, brain tumors)
  • Autoimmune diseases, such as lupus or Sjogren syndrome
  • Strep throat, sinus problems, or nasal polyps that interfere with taste and smell
  • Smoking, because of chemicals that diminish the sense of taste
  • Exposure to harmful chemicals (insecticides)
  • Dental problems, such as ill-fitting dentures
  • Radiation to the head or neck (for cancer treatment)
  • Allergies, because of temporary nasal congestion
  • Hormonal changes, especially estrogen and progesterone
  • Vitamin deficiency (rare)

Aging and Loss of Taste

Age also is a factor in taste loss. People are born with about 10,000 taste buds, with peak function between the ages of 30 and 60. Your sense capacities will gradually decline with age.

When to Seek Medical Attention

Any loss of taste that is not anticipated by your healthcare provider should be evaluated.

Our senses of smell and taste are important for our nutritional status, and individuals who lose these senses often lose weight. Our sense of smell can also warn us of danger, including smoke from a fire, chemicals, or a natural gas leak.

Diagnosing problems with taste or smell is generally uncomplicated. You should see an otolaryngologist (ENT) if you can't taste anything. This healthcare provider, who specializes in disorders of the ear, nose, and mouth, will probably have you try to identify certain chemical odors using a standard "scratch and sniff" test, or flavors (a taste test).

Can Taste Loss Be Treated?

Sometimes, losing your sense of taste or smell is only temporary but sometimes it is permanent. For example, nasal polyps can be removed surgically but lost cells due to the normal aging process cannot be replaced.

Permanent Loss:

  • Severe infections (like those that lead to Bell's palsy)
  • Stroke or head injury (most likely permanent)
  • Chemical exposure or radiation

Treatable Loss:

  • Acute infections like strep throat after resolution
  • Allergies can be treated with antihistamines
  • Smoking, with loss of taste reversed if you quit

Medications that cause dry mouth can lead to a loss of taste. This is because saliva contains important chemical messengers that are necessary for the brain to interpret tastes. In this case, you can discuss a medication change with your healthcare provider. You also can try chewing sugar-free gum and drinking a lot of water. 

Malnutrition and depression can result from prolonged or untreated loss of taste. If the loss of taste is permanent, it is important to work with your medical team to minimize your nutritional or depression risks.

Summary

The loss of taste can occur for a variety of reasons, including a head injury, smoking, a temporary infection, or a chemical exposure. Because your sense of taste also relies on your sense of smell, conditions like nasal congestion may affect taste too.

In most cases, your loss of taste will be temporary and does not suggest a serious problem. If your sense of taste does not return, though, be sure to speak to your healthcare provider as this may point to a more significant or chronic underlying disease.

Frequently Asked Questions

  • Can you regain your sense of smell and taste after losing them to COVID-19?

    Yes. Fortunately, these resolve spontaneously within two to three weeks for most people. If not, see your healthcare provider. Olfactory training (exposure to different smells to retrain your brain) and steroids may help.

  • What should you do if you've lost your sense of smell and taste due to COVID-19?

    Get tested, isolate, and wait for your sense of taste to return. Be sure that you continue to eat healthy foods to maintain your strength and overall nutrition.

  • What causes loss of taste during pregnancy?

    Pregnancy doesn't cause a loss of your sense of taste, but it can change it. Some find normally appetizing things revolting, while others may have a chronic metallic or sour taste in the mouth. This is due to pregnancy hormones.

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5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading
  • American Academy of Otolaryngology Head and Neck Surgery. Smell and Taste.