It used to be believed that the tongue was divided like a map into sections responsible for tasting things that are salty, sweet, bitter, and sour. Scientists have more recently learned that taste buds on every part of the tongue are able to detect every kind of taste quality.
The most common taste disorders include phantom taste perception, a condition where taste is present even when there is nothing in the mouth; dysgeusia, a condition where a foul taste persists in the mouth; and burning mouth syndrome.
Anatomy
Taste buds exist primarily in the small bumps on your tongue, called papillae. They also are present in other parts of the mouth, like the palate and throat. There are four types of papillae:
Filiform: The most common, covering the tough surface of the tongue, and do not contain taste budsFungiform: Located near the front of the tongueCircumvallate: Located near the back of the tongueFoliate: Located on the sides of the tongue
Taste buds develop in utero and scientists believe they are functional by 10 to 13 weeks of gestation. Fetuses are able to taste foods in the maternal diet that pass through the amniotic fluid. Tastes of the maternal diet are also detected in breast milk.
Function
The taste receptor cells that make up taste buds are responsible for sending perceptions of taste to the brain. These cells regenerate quickly and have an average lifespan of only eight to 12 days.
Human brains are able to detect five basic tastes:
BitterSweetSaltySourUmami (savory)
While most people notice a distinction between these categories of tastes, not everyone tastes things in the same way. That’s because of how taste buds detect certain molecules varies from person to person.
Supertasters have more papillae on their tongues, which can make flavors overwhelming. As a result, supertasters tend to prefer milder foods. Conversely, subtasters have fewer papillae. They aren’t as sensitive to strong flavors and tend to prefer more pronounced flavors and spicier foods.
Associated Conditions
Taste disorders affect more than 200,000 people in the U.S. each year. Scientists believe that as many as 15% of adults may have trouble with taste or smell. Many do not seek treatment.
Phantom taste perception, called dysgeusia, is the most common taste disorder. It is characterized by a lingering taste, often bitter or sour, even when there is nothing in your mouth.
Hypogeusia is when a person has a reduced ability to taste things. A complete lack of ability to taste anything is called ageusia. True taste loss is rare. Often an inability to taste is related to a loss of smell due to congestion.
Burning mouth syndrome is a painful condition, where a person experiences a burning sensation in the mouth. It can sometimes last for months. It is most common in older adults.
Taste disorders are most often the result of illness or injury. More rarely, people are born with them. Ear infections, upper respiratory illnesses, radiation treatment for cancer, certain medications, surgeries to the ear, nose, and throat, and dental problems can all contribute to taste disorders.
People frequently burn their tongues on hot foods and beverages. Injuries to the tongue also commonly occur. You may bite your tongue as a result of another trauma or while eating. You might also sustain an injury to your tongue from orthodontia or mouth jewelry.
A swollen tongue is known as glossitis. When your tongue becomes inflamed, it may also affect your taste buds and cause an unusual taste in your mouth. Glossitis can happen as a result of an allergic reaction, injury, infection, or side effects of medication.
Any swelling in the mouth can indicate an allergic reaction, so you should pay close attention to tongue swelling and seek medical attention if it continues to get worse.
Tests
Taste disorders are diagnosed by an ear, nose, and throat (ENT) healthcare provider. Symptoms of taste disorders may include things like loss of taste or smell, or tastes that were formerly pleasant become suddenly offensive.
Along with a physical exam and taking your medical history, your healthcare provider will test your smell and taste perception. This may involve measuring the lowest strength of a chemical that you can recognize, comparing taste and smell of different chemicals, and “scratch and sniff” tests.
Treatment for taste disorders may involve adjusting medication you are on if it is believed to be interfering with your sense of taste or smell, identifying and correcting an underlying medical condition, identifying and removing obstructions in your mouth that may be causing the problem, and smoking cessation.
Taste disorders can affect your ability to maintain an adequate diet because when foods don’t taste good, you may be less inclined to eat as often or as balanced as you otherwise would. It is important to talk to your healthcare provider if you notice a loss or change in your sense of taste or smell.
Treatment for burning mouth syndrome includes pain management. Certain antidepressants and benzodiazepines have also been shown to help.
Most often at-home treatment for minor burns of the tongue is sufficient. Sipping cool water can help ease the pain and stop the burn from continuing to damage your tissue. If you suffer a chemical burn, you should run water over your tongue and not swallow and contact poison control or 911 right away.
If a swollen tongue is believed to be allergies, especially if it is believed to be a symptom of anaphylaxis, treatment will involve reducing the swelling. Your healthcare provider will also work with you to identify the trigger so it is less likely to happen in the future.
At-home treatment for minor swelling includes rising with salt water, sucking on ice to reduce swelling, and avoiding foods that may irritate your tongue, like acidic and salty foods.
Most tongue injuries are minor and heal on their own. If they are more severe, they may require stitches and/or antibiotics. At-home treatment involves eating soft foods, sucking on ice or popsicles, and rinsing with warm salt water.