Oral issues, sinus problems, and medications could all cause "metal mouth"

By Kristin Hayes, RN 

 Medically reviewed by Benjamin F. Asher, MD

A metallic taste in your mouth is often related to your sense of smell or taste buds. Sinus infections, gingivitis, and oral injuries are some common causes.

Sometimes the cause can be more serious, including diabetes, dementia, or kidney failure. In these cases, a metallic taste would usually be just one of several symptoms. A metallic taste can also be the first sign of anaphylaxis, a serious allergic reaction.

This article offers several explanations for what causes a metallic ("tinny") taste in the mouth. It also covers when it's time to consult a healthcare provider and what steps you can take to minimize the taste in the meantime.

Causes of a Metallic Taste in the Mouth

A metallic taste in the mouth can have a number of potential causes. Some causes are related to the mouth while others aren't.

Gum Disease or Poor Oral Health

Gingivitis or periodontal disease often result from poor oral hygiene. "Poor" means forgoing regular dental check-ups and not brushing or flossing regularly. These habits can leave a metallic taste in your mouth.

Often, the "metal mouth" sensation is caused by bleeding gums—a sure sign of gum disease. Blood is rich in iron, which is why it leaves behind a metallic taste.

Bleeding can also be a sign of oral cavity cancer so if bleeding persists make sure to have your mouth checked for cancer by your dentist, doctor or otolaryngologist (ENT doctor).

Gum disease can and should be treated to avoid complications such as tooth loss.1 If you suspect that gum disease may be causing the metallic taste in your mouth, make an appointment with your dentist.

Burning Mouth Syndrome

This fittingly named syndrome causes a burning sensation on the tongue or mucous membranes inside the mouth. It is often followed by a bitter or metallic taste.2

Medications used to treat burning mouth syndrome include tricyclic antidepressants, benzodiazepines (often used to treat anxiety), and gabapentin (used to treat pain and seizures).

Mouth Injury or Oral Surgery

Mouth injuries (such as biting your tongue) or oral surgery (such as wisdom teeth removal or a tonsillectomy) are surefire ways to spawn a metallic taste in your mouth.

The taste may linger until the bleeding is under control and the wound heals.

Medication and Vitamins

Hundreds of commonly used medications can leave behind a metallic taste because they interact with taste sensations in the brain. Some of the more common meds responsible include:3

• Antibiotics, including metronidazole

• Antidepressants or antipsychotic medications

• Antifungal medications

• Antihistamines

• Blood pressure medications

• Chemotherapy drugs

• Diabetes medications, including metformin

• Diuretics

• Glaucoma medications

• Nicotine patches

• Osteoporosis medications

• Radiation drugs

• Seizure medications, including phenytoin

• Steroids

Vitamins that contain metals, such as copper, iron, and zinc, can also bring about a metallic taste simply because of the ingredients they contain. Women often experience this when taking prenatal vitamins.1

Sinus Problems

Conditions such as upper respiratory infections, colds, sinusitis, enlarged turbinates, deviated septum, or even a middle ear infection can cause abnormalities in your sense of smell and, subsequently, your sense of taste.1

Allergies (such as to tree pollen) can lead to sinus problems and a strange taste in your mouth. Addressing the underlying problem can be the answer.

A loss in the sense of taste is known as dysgeusia. This loss can be accompanied by a metallic or smoky taste in the mouth.4

Pregnancy

Hormonal changes during pregnancy can cause disturbances in taste and smell. These changes may manifest as a metallic taste in your mouth.5

Like morning sickness, the unusual taste is often more common in the first trimester than later in pregnancy.

Food Allergies and Anaphylaxis

Specific food allergies, such as to shellfish and tree nuts, have been known to cause an metallic taste in the mouth.

It could also be an early symptom of a serious allergic reaction called anaphylaxis. The metallic taste can begin almost immediately, prior to other symptoms of anaphylaxis.

These symptoms include swelling, itchy skin, difficulty breathing, wheezing, nausea or vomiting, headaches, and disorientation.6

Anaphylaxis is life-threatening. If you suspect that you or someone you know is experiencing an anaphylactic reaction, call 911 immediately.

Exposure to Mercury or Lead

Exposure to certain chemical elements such as mercury or lead can cause a metallic taste in the mouth. You can encounter lead in old building materials such as chipped or flaking paint. It can also be present in contaminated water.

Mercury may be found in contaminated water or in some of the foods you eat, such as fish.

If you think you or your child might have been exposed to mercury or lead, contact your healthcare provider. 

Diabetes and Low Blood Sugar

Diabetes and low blood sugar are both known to cause taste disturbances, including a metallic taste in the mouth.1

A common diabetes medication, metformin, is also a likely trigger.

Neurological Diseases

Neurological problems, such as Alzheimer's disease or other types of dementia, can cause the brain to misinterpret signals coming from the taste buds. This can result in loss of appetite and a metallic taste in the mouth.1

Other neurological problems that can set off this reaction include:

• Bell's palsy

• Brain injury or tumors

• Multiple sclerosis

• Parkinson's disease

• Stroke

Kidney Failure

Another serious cause of a metallic taste in your mouth is kidney failure. Uremic toxicity (excessive uric acid), which is due to a loss of kidney function, can cause taste changes.

Keep in mind that this is one of many possible signs of kidney problems.7

Sjogren's syndrome

Sjogren's syndrome is an immune disorder that causes a decrease in the amount of saliva in your mouth. Some people with Sjogren's syndrome report experiencing a metallic taste in the mouth.  

When to See a Healthcare Provider

A brief flash of a metallic taste in your mouth is usually nothing to worry about. In fact, if you've recently started taking a new medication, there's a good chance it's the cause. It should go away as your body adjusts to the medicine.

See your healthcare provider if the sensation persists or you develop other worrisome symptoms, like a fever.

Coping With a Metallic Taste

The best ways to treat and prevent that metallic taste in your mouth will depend on the cause. However, a few general strategies may make it more bearable in the meantime. Consider:

• Brushing and flossing after meals

• Chewing on sugar-free gum between meals

• Masking the taste of metal with herbs, spices, and sweet condiments

• Quitting smoking

• Staying hydrated (a dry mouth can intensify the metallic taste, so drink water or eat ice chips)

• Swapping your metal utensils for plastic ones, at least temporarily

Summary

Gum disease and poor oral hygiene are two likely reasons why you may be experiencing a metallic taste in your mouth. So are burning mouth syndrome and a mouth injury or recent oral surgery. Medication, vitamins, a food allergy, and sinus problems can also cause the unpleasant sensation.

It's usually nothing to worry about unless the taste persists or you develop other symptoms, like a fever. Then it's time to see your healthcare provider. In the meantime, a few coping tactics can help minimize the taste.

Sources

Cleveland Clinic. 8 possible causes for that metallic taste in your mouth.

Kamala KA, Sankethguddad S, Sujith SG, Tantradi P. Burning mouth syndrome. Indian J Palliat Care. 2016;22(1):74–79. doi:10.4103/0973-1075.173942

Douglass R, Heckman G. Drug-related taste disturbance: a contributing factor in geriatric syndromes. Can Fam Physician. 2010;56(11):1142–1147.

Science Direct. Parageusia.

Cleveland Clinic. Common causes for a metallic taste in your mouth.

Cleveland Clinic. Anaphylaxis.

National Institute of Diabetes and Digestive and Kidney Diseases. Lesson 3: What happens when kidney disease gets worse.

By Kristin Hayes, RN
Kristin Hayes, RN, is a registered nurse specializing in ear, nose, and throat disorders for both adults and children.