Bad taste and changes to your tongue
A bad or changed taste can come from gum disease, a mouth infection, dry mouth, a medicine or a cold. See a dentist or GP about any red or white patch in your mouth, or an ulcer that lasts more than 3 weeks.
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A taste that will not shift, or a tongue that looks or feels different, is easy to fret over. The NHS says a metallic taste is not usually serious, and that a sore or white tongue is not usually serious and is often easily treated. A few causes do need checking, though.
What can cause a bad taste in your mouth?
There are many possible causes, and some have nothing to do with your teeth.
Gum disease
Gum disease is caused by plaque building up on your teeth and irritating your gums. The NHS says it can lead to bad breath and a bad taste in your mouth, and that symptoms include gums that bleed when you brush or floss, or that become swollen, red and sore. It is very common, and the NHS says it is important to have it checked by a dentist.
Infection in the mouth
A dental abscess is a build-up of pus caused by an infection, and a bad taste is one of its symptoms, the NHS says. Its other symptoms include intense tooth or gum pain and a swollen face or jaw. It will not go away on its own and needs urgent treatment by a dentist. Oral thrush, a fungal infection, can also leave an unpleasant taste. It is covered below.
Dry mouth
Saliva helps protect your teeth and gums. The Oral Health Foundation lists changes in taste among the signs of dry mouth, and says that without enough saliva you may be more likely to have tooth decay, gum disease and mouth infections. Some prescription medicines, radiotherapy to the head, neck or mouth, and some health conditions can all reduce saliva.
The Oral Health Foundation advises speaking to your dental team, doctor or pharmacist if a dry mouth is ongoing or severe.
Medicines
The NHS gives metronidazole and zopiclone as examples of medicines that can cause a metallic taste. If you think a medicine is responsible, speak to a pharmacist. The NHS says not to stop a prescribed medicine without medical advice.
Colds, indigestion and other causes
Colds, sinus infections and other airway problems, indigestion, pregnancy, and cancer treatments such as chemotherapy and radiotherapy can all cause a metallic taste, according to the NHS. With a cold or indigestion, the taste should go away once the problem has cleared up or been treated. In pregnancy it is usually temporary. A lost or changed sense of smell can also cause it. Our guide to health conditions and your teeth covers how pregnancy and cancer treatment can affect your mouth.
See a GP if a metallic taste does not go away or has no obvious cause, the NHS says.
What can tongue changes mean?
The NHS says a white tongue can be a sign of a health condition, such as anaemia, scarlet fever, lichen planus, leukoplakia, geographic tongue, mouth ulcers or oral thrush. It also says not to diagnose yourself, and to see a GP if you are worried. Leukoplakia, for example, causes white, raised patches that do not rub off. The NHS says to see a GP or dentist if you have white patches on your tongue, whatever the cause. Oral thrush and geographic tongue are explained below.
Oral thrush
Oral thrush is an infection caused by a fungus called Candida, and the NHS says it is usually harmless. In adults the inside of the mouth looks red with white patches, which leave red spots that can bleed when wiped off. Other signs include cracks at the corners of the mouth, not tasting things properly, an unpleasant taste, and pain such as a sore tongue. Oral thrush in adults is not contagious.
The NHS says you may be more likely to get it if you take antibiotics over a long time, use asthma inhalers or are having cancer treatment. It is common in babies, and in older people with dentures. A pharmacist can advise on a mouth gel. The NHS says to see a GP if there is no improvement after 1 week of using the gel, if swallowing is difficult or painful, or if a baby under 4 months has signs of it. If you wear dentures, the NHS says not to wear them at night, and to see your dentist if they do not fit properly.
Geographic tongue
The Oral Health Foundation describes geographic tongue as a common, harmless condition. Irregular, smooth red patches with pale or white edges appear on the top or sides of the tongue, and can look like the outline of a map. They come from the surface of the tongue renewing itself unevenly, and they can change shape or move over time.
Many people have no symptoms. Some notice soreness or a burning feeling, particularly with acidic, hot, spicy or very salty food. It is not an infection, and the Oral Health Foundation says it does not become cancerous. Most people need no treatment, and it says your dental team can check changes that are painful, worrying or not improving. Patches on the tongue can look alike, so if you have not had a patch checked before, ask a dentist or GP to look at it rather than assuming it is geographic tongue.
A sore tongue
Biting or burning your tongue on hot food or drink can cause pain and swelling, which the NHS says should only last a few days. For a sore or white tongue, the NHS suggests:
- using a soft toothbrush
- brushing your tongue, or using a scraper, to help improve a white tongue
- drinking cool drinks through a straw
- avoiding spicy, acidic or hot food and drink
- avoiding toothpaste that contains sodium lauryl sulphate
- avoiding smoking and alcohol
A pharmacist can say what might help with pain or irritation, and whether you should see a dentist or GP.
When to see a dentist
The NHS says to see a GP about the signs below, and that a dentist can also help with ulcers, lumps, patches or pain in your mouth. For a red or white patch there is no waiting time: the NHS says to see a GP if you have one. The 3 week limit applies to ulcers only.
- a mouth ulcer that has lasted more than 3 weeks
- a red or white patch inside your mouth, including white patches on your tongue
- a lump in your mouth, on your lip, or in your neck or throat
- pain inside your mouth that is not going away
- difficulty swallowing or speaking, or a hoarse voice that does not go away
- tongue pain or itchiness that does not go away or gets worse
The ulcer, patch, lump, pain, swallowing and voice signs are on the NHS list of possible symptoms of mouth cancer. The NHS says these symptoms are very common and can be caused by other conditions. Having them does not definitely mean you have mouth cancer, but it is important to get checked by a GP or dentist. If cancer is the cause, finding it early may mean it is easier to treat.
Gums and taste are separate matters. See a dentist if your gums bleed when you brush, or are painful and swollen. See a GP if a metallic taste does not go away or has no obvious cause.
If you think you have a dental abscess, the NHS says to ask for an urgent dentist appointment or get help from NHS 111. Signs include a bad taste, intense tooth or gum pain, a swollen face or jaw, and a high temperature. The NHS says not to go to a GP surgery for this, because a GP cannot give dental treatment.
The NHS says to call 999 or go to A&E if any of the following happen. It says not to drive yourself, and to ask someone to drive you or call 999 and ask for an ambulance.
- you find it hard to breathe, speak or swallow
- you have a swollen or painful eye, or suddenly start having problems with your eyesight
- you have a lot of swelling in your mouth
- you find it hard to open your mouth
What we would do
For a bad taste or tongue change that has not settled, we would start with a new patient exam. We examine your teeth, gums and soft tissues and carry out an oral cancer screening, so tell us about anything you have noticed on your tongue. We take small X-rays where needed and explain what we find in plain language.
If plaque and gum health look like the cause, a dental hygiene appointment removes plaque and tartar, picks up early signs of gum disease and includes advice on brushing and flossing. Some causes sit outside the mouth, such as a medicine, a cold or indigestion. For those, the NHS points to a pharmacist or GP.
To arrange a check, book an appointment and tell us what you have noticed.
Want us to take a look?
Book an appointment at whichever of our five practices suits you. We will check what is going on and talk you through your options.
Questions this guide answers
Why do I have a metallic taste in my mouth?
The NHS lists gum disease, certain medicines, cancer treatments, colds and sinus infections, indigestion and pregnancy among the common causes. It says a metallic taste is not usually serious, and to see a GP if it does not go away or has no obvious cause.
Is a white tongue serious?
The NHS says a sore or white tongue is not usually serious and is often easily treated. It can be a sign of a health condition, though, so the NHS advises seeing a GP or dentist if you have white patches on your tongue, or pain or itchiness that does not go away.
Can my medicine change how things taste?
Yes, some can. The NHS names metronidazole and zopiclone as examples of medicines that can cause a metallic taste. It advises speaking to a pharmacist and not stopping a prescribed medicine without medical advice.
How long should I wait before getting a mouth ulcer checked?
The NHS says to see a GP if you have a mouth ulcer that has lasted more than 3 weeks, and adds that a dentist can also help with ulcers, lumps, patches or pain in your mouth. The 3 weeks applies to ulcers only: for a red or white patch in your mouth, the NHS says to see a GP if you have one.
