A metallic taste in the mouth can be unpleasant and is not that uncommon. There are several possible explanations for the condition ranging from those which can be easily remedied to more serious underlying medical problems.
Metallic taste in mouth causes
A common cause is from bleeding, because the pigment in red blood cells contains iron. If you bite your tongue by accident, suffer trauma to the mouth, or have gum disease which can cause spontaneous bleeding from inflamed gums, then you will likely have a metal taste for a while, or notice it now and again.
Having such a taste in your mouth can also be caused by medication or by a physical condition which triggers an upset in your body chemistry.
Infection in the mouth and gingivitis, or gum disease, are localised causes but there might be an underlying more general cause, such as pregnancy causing hormonal changes, or an illness such as kidney stones, heart failure, diabetes or cancer.
Toxicity from a poison such as lead or mercury is another possibility. Amalgam fillings when new, or conversely when very old, can give off small amounts of mercury vapour and a slight metallic taste. The amounts of mercury released, however, are so small that this is not generally recognized (by scientific review) as a health problem.
There is a rare form of poisoning caused by plankton-eating fish such as herring and sardines called clupeotoxin poisoning and this can be quite serious.
Some vitamin supplements might induce a metal taste, but conversely a deficiency in some vitamins such as B12 or of minerals like zinc, can have a similar effect.
You might also become aware of a metallic taste if your sense of smell has recently been impaired, perhaps as a result of a cold, allergy, sinusitis, or nasal polyps. A metal taste is often experiencing when one has a persistent cough.
Other causes of the problem include smoking, dehydration, or reduced salivary gland function. A sore throat or antibiotic therapy can also disturb your sense of taste, at least for a while.
The sensation has been noticed by people suffering from head and neck conditions such as cancer or Bell’s palsy, or conditions like gastroesophageal reflux, diabetes, or Parkinson’s.
Most often, however,this issue results simply from poor oral hygiene inducing a chronic inflammation of the gums, together with other unhealthy lifestyle factors such as smoking.
The remedy for a metallic taste in your mouth depends, of course, on identifying the factor(s) causing the condition and eradicating them. This can often be simply a matter of undertaking proper, thorough tooth-brushing and flossing and giving up unhealthy habits such as smoking or heavy drinking.
Anyone who has a persistent bad taste in their mouth despite practising good oral hygiene, should check with their dentist for possible causes like gum disease, and then if necessary also see their doctor to check for any general systemic disease.
Keeping well hydrated during the course of a day helps to combat bad tastes, and a quick clean of the teeth in a mirror using dental floss after lunch can help keep the breath fresh and the mouth free from unpleasant tastes.
Advocates of certain branches of medicine such as traditional Chinese might interpret a metal taste in the mouth as indicative of a general body imbalance brought on by factors such as inadequate sleep, a poor diet, or too much stress. These could certainly be contributory factors to some degree and might warrant consideration.
A metallic taste can occur occasionally for reasons mentioned and is very rarely a serious sign. But a persistent problem needs to be investigated to determine the cause and remedy.