Metallic taste in the mouth: common causes and what to do

Taste depends on the tongue, but also on smell, saliva and the state of the teeth and gums, which is why a metallic taste has so many possible explanations. The NHS says there are lots of possible causes and that it is not usually serious. nidirect, which adapts NHS content, says the same: a metallic taste is not usually serious and can be a symptom of many different things, and treatment depends on the cause.

In practice, the most useful clue is what else has changed. A new medicine, a course of treatment, a cold, a dental problem or a pregnancy each point towards a particular explanation and each has its own simple response.

The NHS page sets out a short list of common causes alongside what can be done for each one.

The NHS gum disease page lists a bad taste in the mouth, together with bad breath, among the things gum disease can lead to, and its main symptoms are gums that bleed when brushing, flossing or eating hard foods and gums that are swollen, red and sore. The Oral Health Foundation lists a bad taste in the mouth among the signs of gingivitis, the early stage of gum disease. A dentist can identify and treat this.

Oral thrush is another mouth cause. The NHS lists an unpleasant taste and not tasting things properly among its symptoms in adults, and treatment is with an antifungal gel. A dry mouth can also matter: the NHS dry mouth page lists problems with your sense of taste that are not going away among the reasons to see a GP, and names dehydration, medicines, mouth breathing, anxiety, cancer treatment and oral thrush among its causes.

Some medicines are named by the NHS: metronidazole, an antibiotic, and zopiclone, a sleeping tablet. nidirect uses the wider category of medicines such as antibiotics. The advice is the same in both: speak to a pharmacist, who can check the medicine leaflet and tell you whether a taste change is a known effect, and do not stop prescribed medicine without medical advice.

People having chemotherapy or radiotherapy often notice taste changes. The NHS suggests eating stronger-tasting foods such as ginger and spices and sucking boiled sweets. Your cancer team can advise further if it is affecting eating.

The NHS says colds, sinus infections and other problems with the airways can cause the taste and that it should go away once the problem has cleared up. It also says a lost or changed sense of smell can sometimes cause a metallic taste, and nidirect points to a possible link with a problem with the sense of smell. Indigestion is a further cause, with the taste expected to go away after the indigestion is treated.

In pregnancy the NHS describes the taste as usually temporary, clearing up by itself, so no particular treatment is needed.

The NHS and nidirect both say to see a GP if the metallic taste does not go away or has no obvious cause. nidirect adds that you can speak to a GP or dentist. A dentist is a sensible first stop if you also have bleeding or sore gums, a bad smell on the breath or toothache; a GP is a sensible first stop if the taste came with a new medicine, ongoing sinus symptoms or a change in smell.

It is helpful to note when the taste began, whether it is constant or comes and goes, whether any medicine or supplement was started around that time, and whether it is accompanied by dry mouth, gum problems, reflux or loss of smell. This is the information the clinician will ask for.