Problems with the sense of taste can have a big impact on life. Taste stimulates the desire to eat and therefore plays a key role in nutrition. The sense of taste also helps keep us healthy by helping us detect spoiled food or drinks.

Scientists have established that there are five distinct flavors that contribute to our sense of taste: sweet, sour, bitter, salty, and savory.

These flavors, plus the sensations of heat, coolness, and texture combine inside the mouth to give us a sense of taste. The sense of smell also adds to the perception of taste. In fact, the senses of taste and smell are so closely related that most people who go to the doctor thinking they have lost their sense of taste are surprised to discover that they have lost their sense of smell.

Losing your sense of taste can even affect your health. Here’s how: When taste is impaired, you might change your eating habits by adding too much sugar or salt to your food to try to make it taste better. You may also eat too much or too little.

Many of us take our sense of taste for granted, but a taste disorder can have a negative effect on your health and quality of life. If you are having a problem with your sense of taste, you are not alone. More than 200,000 people visit a doctor each year for problems with their ability to taste or smell. Scientists believe that up to 15 percent of adults might have a taste or smell problem, but many don’t seek a doctor’s help.

The senses of taste and smell are very closely related. Most people who go to the doctor because they think they have lost their sense of taste are surprised to learn that they have a smell disorder instead.

Your ability to taste comes from tiny molecules released when you chew, drink, or digest food; these molecules stimulate special sensory cells in the mouth and throat. These taste cells, or gustatory cells, are clustered within the taste buds of the tongue and roof of the mouth, and along the lining of the throat. Many of the small bumps on the tip of your tongue contain taste buds. At birth, you have about 10,000 taste buds, but after age 50, you may start to lose them.

When the taste cells are stimulated, they send messages through three specialized taste nerves to the brain, where specific tastes are identified. Taste cells have receptors that respond to one of at least five basic taste qualities: sweet, sour, bitter, salty, and umami [oo-MOM-ee]. Umami, or savory, is the taste you get from glutamate, which is found in chicken broth, meat extracts, and some cheeses. A common misconception is that taste cells that respond to different tastes are found in separate regions of the tongue. In humans, the different types of taste cells are scattered throughout the tongue.

Taste quality is just one way that you experience a certain food. Another chemosensory mechanism, called the common chemical sense, involves thousands of nerve endings, especially on the moist surfaces of the eyes, nose, mouth, and throat. These nerve endings give rise to sensations such as the coolness of mint and the burning or irritation of chili peppers. Other specialized nerves create the sensations of heat, cold, and texture. When you eat, the sensations from the five taste qualities, together with the sensations from the common chemical sense and the sensations of heat, cold, and texture, combine with a food’s aroma to produce a perception of flavor. It is flavor that lets you know whether you are eating a pear or an apple.

Most people who think they have a taste disorder actually have a problem with smell. When you chew food, aromas are released that activate your sense of smell by way of a special channel that connects the roof of the throat to the nose. If this channel is blocked, such as when your nose is stuffed up by a cold or flu, odors can’t reach sensory cells in the nose that are stimulated by smells. As a result, you lose much of our enjoyment of flavor. Without smell, foods tend to taste bland and have little or no flavor.

The most common taste disorder is phantom taste perception: a lingering, often unpleasant taste even though there is nothing in your mouth. People can also experience a reduced ability to taste sweet, sour, bitter, salty, and umami—a condition called hypogeusia [hy-po-GYOO-zee-a]. Some people can’t detect any tastes, which is called ageusia [ah-GYOO-zee-a]. True taste loss, however, is rare. Most often, people are experiencing a loss of smell instead of a loss of taste.

In other disorders of the chemical senses, an odor, a taste, or a flavor may be distorted. Dysgeusia [dis-GYOO-zee-a] is a condition in which a foul, salty, rancid, or metallic taste sensation persists in the mouth. Dysgeusia is sometimes accompanied by burning mouth syndrome, a condition in which a person experiences a painful burning sensation in the mouth. Although it can affect anyone, burning mouth syndrome is most common in middle-aged and older women.

Some people are born with taste disorders, but most develop them after an injury or illness. Among the causes of taste problems are:

• Upper respiratory and middle ear infections
• Radiation therapy for cancers of the head and neck
• Exposure to chemicals such as insecticides, and some medications, including antibiotics and antihistamines
• Head injury
• Surgery to the ear, nose, and throat (such as middle ear surgery) or extraction of the third molar (wisdom tooth)
• Poor oral hygiene and dental problems.

Many things can cause you to lose your sense of taste. If the salivary glands are damaged or aren’t producing enough saliva, this can affect taste. Most of the time there are ways to help with the problem.

A new loss of taste is a symptom that can occur with coronavirus infection. You should regain your sense of taste after all other symptoms have gone away, however if it doesn’t return, seek medical care as soon as possible.

Medications, like antibiotics and pills to lower cholesterol and blood pressure, can sometimes change how food tastes. Some medicines such as those for high blood pressure, depression, and bladder-control issues can make your mouth dry. Having a dry mouth can cause food to taste funny and also make it hard to swallow. Talk to your doctor if you think a medicine is affecting your sense of taste. There may be different medicines that you can try. Do not stop taking your medicine.

Gum disease, an infection in your mouth, or issues with your dentures can leave a bad taste in your mouth that changes the way food tastes. Brushing your teeth, flossing, and using mouthwash can help prevent these problems. Talk to your dentist if you have a bad taste in your mouth that won’t go away.

Alcohol can alter how food tastes. Cutting back or stopping drinking may help. Smoking can also reduce your sense of taste. Quitting may help.

People who are having cancer treatments might have a problem with taste. Your sense of taste will often return once treatments stop.

Cancer treatments can make food taste bad or “off.” Some say that food tastes metallic. This funny taste may keep some people from eating healthy food. If this happens to you, try to:

• Eat four or five small meals during the day instead of three large meals.
• Eat cold food, including yogurt, pudding, and gelatin dessert. Cold food may taste better than hot food.
• Eat fresh, uncooked vegetables. Cooked vegetables can have strong odors that may not be appealing.
• Drink lots of fluids, including water, weak tea, juice, and ginger ale.
• Test new foods to find ones you like.
• Brush your teeth before and after eating.
• Use plastic forks and spoons if food tastes metallic.
• If food tastes bland, marinate foods to improve their flavor or add spices to foods.
• If red meat tastes strange, switch to other high-protein foods such as chicken, eggs, fish, peanut butter, turkey, beans, or dairy products.
• If foods taste salty, bitter, or acidic, try sweetening them.
• If you have a bad taste in your mouth, try sugar-free lemon drops, gum, or mints.

Taste disorders include:

• Dysgeusia [dis-GYOO-zee-a], a condition in which a foul, salty, rancid, or metallic taste persists in your mouth. Dysgeusia is sometimes accompanied by Burning Mouth Syndrome, which is characterized by a painful burning sensation in your mouth.
• Hypogeusia [hy-po-GYOO-zee-a], in which your ability to taste is reduced.
• Ageusia [ah-GYOO-zee-a], in which you’re unable to taste anything.

Taste disorders can weaken or remove an early warning system that most of us take for granted. Taste helps you detect spoiled food or liquids and, for some people, the presence of ingredients to which they are allergic.

Loss of taste can create serious health issues. A distorted sense of taste can be a risk factor for heart disease, diabetes, stroke, and other illnesses that require sticking to a specific diet. When taste is impaired, a person may change his or her eating habits. Some people may eat too little and lose weight, while others may eat too much and gain weight.

Loss of taste can cause you to add too much sugar or salt to make food taste better. This can be a problem for people with certain medical conditions, such as diabetes or high blood pressure. In severe cases, loss of taste can lead to depression.

If you are experiencing a taste disorder, talk with your doctor.

Taste disorders are diagnosed by an otolaryngologist (sometimes called an ENT – ear, nose, and throat – doctor). An otolaryngologist determines how severe your taste disorder is by using a special taste test that measures the lowest concentration of a taste quality you can detect and recognize. You may be asked to sip a substance, spit it out and then describe the taste. Another type of taste test uses chemicals applied directly to the tongue. You also may be asked to compare the tastes of different substances, or discern the differences between different concentrations of taste qualities. Your doctor will also examine your ears, nose, and throat, and ask about your medical history and oral hygiene habits.

Treatment will depend upon what is causing your taste disorder. If a medication is the cause, your doctor will ask you to stop taking the medication or change to a comparable one that does not affect your sense of taste as much.

If a medical condition is the cause, your doctor will treat the condition or refer you to another doctor who can. Often, treating the medical problem will eliminate the taste disorder. For example, if you’ve lost your sense of taste because of respiratory infections or allergies, you should regain your taste when those conditions resolve.

Some people with a taste disorder will get their taste back spontaneously, without any treatment.

If the foods you enjoy don’t smell or taste the way you think they should, talk to your doctor. He or she might suggest you see a specialist who treats people with smell and taste problems.This kind of doctor is called an otolaryngologist (oh-toh-lar-ing-gol-uh-jist), also known as an ENT (which stands for ear, nose, and throat). An otolaryngologist works on problems related to the ear, nose, and throat, as well as the larynx (voice box), mouth, and parts of the neck and face. The doctor may ask:

• Can you smell anything at all?
• Can you taste any food?
• When did you first notice the problem?
• Is the problem getting worse?
• Have you been told that you have allergies or chronic sinus problems?
• What medicines do you take?

There are likely ways to help fix the problem. If not, the doctor can help you cope with the changes in smell and taste.

If you lose some or all of your sense of taste, here are things you can try to make your food taste better:

• Prepare foods with a variety of colors and textures.
• Use aromatic herbs and spices to add more flavor.
• Work with your doctor or with a nutritionist to identify condiments that you can add to your diet to improve the taste of your food.
• Avoid dishes that combine different foods, such as casseroles, which can hide individual flavors and dilute taste.

If you’re having trouble smelling and tasting your food, try adding color and texture to make your food more interesting. For example, try eating brightly colored vegetables like carrots, sweet potatoes, broccoli, and tomatoes. Also, if your diet allows, flavor your food with a little butter, olive oil, cheese, nuts, or fresh herbs like sage, thyme, or rosemary. To put some zing in your food, add mustard, hot pepper, onions, garlic, ginger, different spices, or lemon or lime juice. Choose foods that look good to you.

The National Institute on Deafness and Other Communication Disorders (NIDCD) supports basic and clinical investigations of smell and taste disorders at its laboratories in Bethesda, Maryland, and at universities and chemosensory research centers across the country. These chemosensory scientists are exploring how to:

• Prevent the effects of aging on taste and smell.
• Develop new diagnostic tests.
• Understand associations between taste disorders and changes in diet and food preferences in the elderly or among people with chronic illnesses.
• Improve treatment methods and rehabilitation strategies.

Some recent chemosensory research focuses on identifying the key receptors expressed by taste cells and understanding how those receptors send signals to the brain. Researchers are also working to develop a better understanding of how sweet and bitter substances attach to their targeted receptors. This research holds promise for the development of sugar or salt substitutes that could help combat obesity or hypertension, as well as the development of bitter blockers that could make life-saving medicines more acceptable to children. Taste cells—as well as sensory cells that help you smell—are the only sensory cells in the human body that are regularly replaced throughout life. Researchers are exploring how and why this happens so that they might find ways to replace other damaged sensory cells.

NIDCD-funded researchers have shown that small variations in our genetic code can raise or lower our sensitivity to sweet tastes, which might influence our desire for sweets. Scientists are also working to find out why some medications and medical procedures can have a harmful effect on our senses of taste and smell. They hope to develop treatments to help restore the sense of taste to people who have lost it.

Scientists are gaining a better understanding of why the same receptor that helps your tongue detect sweet taste can also be found in the human gut. NIDCD-funded scientists have shown that the sweet receptor helps the intestine to sense and absorb sugar and turn up the production of blood sugar-regulation hormones, including the hormone that regulates insulin release. Further research may help scientists develop drugs targeting the gut taste receptors to treat obesity and diabetes.