Taste - impaired

Impaired taste is a change in how you experience food and drinks. Taste may be weaker than usual, completely absent, or unpleasantly altered. Medical terms include hypogeusia for reduced taste, ageusia for loss of taste, and dysgeusia for distorted taste.

Your tongue detects basic tastes such as sweet, salty, sour, bitter, and savoury. Much of what people call “taste” is actually flavour created by the sense of smell. If a cold or blocked nose stops aromas reaching the smell receptors high inside your nose, food may seem bland even though your tongue still detects basic tastes.

Impaired taste is a symptom, not a diagnosis. It has many possible causes, and the pattern and duration can help narrow them down.

You may notice that:

• Food tastes weaker or has no flavour
• Sweet, salty, sour, bitter, or savoury tastes are harder to identify
• Familiar foods taste metallic, bitter, burnt, or otherwise wrong
• An unpleasant taste remains when you are not eating
• You add more salt, sugar, or seasoning to notice flavour
• Eating feels less enjoyable, affecting your appetite

A simple clue is whether you can still detect sugar as sweet or lemon as sour while being unable to recognise a familiar food’s flavour. This may suggest that smell, rather than taste itself, is mainly affected. It is not a definitive home test.

Changes in smell, dry mouth, mouth pain, dental problems, or nasal blockage may occur at the same time.

Respiratory infections are common causes of a changed sense of taste or flavour. These include colds, influenza, and COVID-19. Nasal swelling and mucus can reduce smell, while some infections may also affect the smell or taste pathways directly.

Other common causes include:

• Nasal blockage: Allergies, sinus inflammation, or nasal polyps can prevent aromas reaching smell receptors
• Dry mouth: Saliva helps dissolve food chemicals so they can reach taste receptors
• Medicines: Some antibiotics like amoxicillin or doxycycline, blood pressure medicines, antidepressants like sertraline or fluoxetine, and other medicines can alter taste
• Mouth or dental problems: Gum disease, tooth decay, oral infections, and poorly fitting dental appliances may contribute
• Smoking: Tobacco can weaken taste and smell
• Age-related change: Taste and smell may become less sensitive over time

Less common causes include a head injury, surgery involving the ear or throat, radiation treatment to the head or neck, or damage to nerves involved in taste. Certain vitamin or mineral deficiencies can affect taste, but testing is usually needed before assuming a deficiency or taking supplements.

Neurological conditions, autoimmune diseases, and growths affecting the nose, mouth, brain, or related nerves are possible but less common. Impaired taste alone does not show that one of these conditions is present.

Call emergency services if a sudden taste change occurs with signs that could indicate a stroke, such as:

• Facial drooping
• Weakness or numbness on one side
• Trouble speaking or understanding speech
• Sudden severe dizziness, loss of balance, or vision change

Seek same-day medical advice if the change follows a significant head injury, or if swelling of the tongue or throat makes it difficult to breathe or swallow. Breathing difficulty is an emergency.

Arrange a routine appointment if impaired taste lasts several weeks, keeps worsening, repeatedly returns, or has no clear explanation. You should also book an appointment if it is causing weight loss, poor nutrition, difficulty eating, persistent mouth sores, dental pain, or severe dry mouth.

A taste change that begins after starting a medicine should be discussed with a doctor or pharmacist. Do not stop a prescribed medicine on your own unless you are advised to do so.

A clinician will ask when the change began, whether it was sudden or gradual, and whether taste is reduced, absent, or distorted. They may ask about recent infections, nasal symptoms, mouth problems, head injuries, smoking, and new or changed medicines.

Your mouth, teeth, tongue, nose, ears, and throat may be examined. The examination may also check facial movement and other nerve functions.

Taste testing can involve small amounts of sweet, salty, sour, or bitter substances. Smell identification tests may help show whether a perceived taste problem is mainly due to reduced smell.

Blood tests are not always needed. They may be used when the history suggests a nutritional deficiency, thyroid problem, diabetes, or another medical condition. Imaging or referral to an ear, nose, and throat specialist may be considered after an injury, with one-sided symptoms, or when the cause remains unclear.

Treatment depends on the cause. Taste or flavour often improves as a cold, nasal congestion, or mouth problem settles. Dental treatment may help when tooth or gum disease is involved. A clinician may adjust a medicine if a suitable alternative is available.

While recovering, you can try:

• Drinking enough water and managing dry mouth as advised
• Brushing your teeth and tongue gently and cleaning between teeth
• Using herbs, spices, acidity, or different textures to make food appealing
• Trying foods at different temperatures
• Eating smaller, regular meals if your appetite is reduced
• Avoiding smoking and second-hand smoke

Avoid adding large amounts of salt or sugar to compensate for weak flavour, especially if you have been advised to limit them. Do not take zinc or other supplements specifically for taste loss unless a clinician has identified a need.

Reduced smell can make it harder to notice smoke, gas, or spoiled food. Check smoke alarms, follow use-by dates, and ask someone else to assess food if you are unsure.

The outlook depends on what caused the change. Flavour reduced by a blocked nose may improve as the blockage clears. Changes after a respiratory infection often improve gradually, but recovery can take weeks or months.

Taste changes caused by dry mouth, dental disease, smoking, or medicine may improve when the contributing issue is addressed. Recovery after nerve injury is less predictable and may be incomplete.

If eating becomes difficult, early support matters. A clinician or dietitian can help you maintain adequate nutrition without relying on excess salt or sugar.

Is loss of taste the same as loss of smell?

No. They are separate senses, but they work closely together. Many people who say they have lost taste can still detect basic tastes but have lost flavour because their sense of smell is reduced.

Can COVID-19 affect taste?

Yes. COVID-19 can alter smell, taste, or both. Other respiratory infections can do this as well, so the symptom alone cannot identify the infection.

Could a medicine be responsible?

Yes. Many medicines can alter taste directly or by causing dry mouth. Ask a doctor or pharmacist to review your medicines rather than stopping one yourself.

Should I take zinc?

Not without advice. Zinc deficiency can affect taste, but supplements do not treat every cause and excessive zinc can be harmful. Testing or clinical assessment may be needed.

Can impaired taste affect health?

It can reduce appetite or lead you to add excess salt or sugar. Persistent symptoms may contribute to weight loss or poor nutrition, especially if eating has become unpleasant.