Taste, one of the five senses, is a combination of various sensations that tell the brain how something tastes.
Along with thousands of sensory organs called taste buds and taste papillae on the tongue, smell, texture, and temperature also play large roles in taste. Someone with a stuffy nose may not be able to enjoy their favorite meal because an important part in creating that taste is impaired.
With the information the tongue sends to the brain, the brain sorts taste into five basic categories: sweet, sour, salty, bitter, and savory. It’s a common mistake that taste buds only register certain tastes on certain regions of the tongue.
Because there are many factors involved in the sense of taste, taste disorders can be a result of various different conditions or bodily imbalances. Metallic taste, or dysgeusia, can occur as the body responds to a foreign substance. It can also be a warning sign of other health problems.
There are a number of common things that can cause a metallic taste. Some are more serious than others but most can be resolved easily or will go away on their own.
Metallic taste in someone who is otherwise healthy isn’t usually cause for alarm, says Dr. Michael Rabovsky, a family medicine physician at the Cleveland Clinic. Here is a list of common causes behind metallic taste:
Poor oral health
Those who don’t brush or floss regularly may experience a metallic taste due to gingivitis, periodontitis, or tooth infection. These issues can cause people to bleed after they brush or floss, sometimes resulting in metallic taste.
These issues can also cause more serious infections in the teeth and gums. Dentists can give a prescription drug to clear up infections, after which the metallic taste should go away.
Regular dental cleanings and routine work will help to prevent or treat these issues before they get worse. Recent wisdom tooth removal surgery can also cause a metallic taste.
Because the senses of smell and taste are so closely tied together, sinus issues can impair the ability to taste or cause a metallic taste. A blocked nose is one sign of a sinus issue. Once the sinus problems go away, the metallic taste should as well.
These problems are generally very common and include:
- Common cold
- Sinus infection
- Nasal polyps
- Middle ear or other upper respiratory infections
- Recent middle ear surgery
Sometimes prescription drugs can cause an aftertaste as the body is absorbing them. Metallic taste can also occur if someone experiences dry mouth as a side effect of their medication.
Some common drugs that are known to cause a metallic taste include:
- Antidepressants and other psychiatric medications
- Blood pressure medications
- Glaucoma medications
- Antifungal medications
- Nicotine patches
- Diuretic medications
- Antihistamine medications
- Osteoporosis medications
Cancer treatment therapies
Taste changes are a common side effect of cancer therapies like chemotherapy and radiation to the head and neck. These treatments can cause damage to the taste buds and salivary glands, sometimes resulting in a metallic taste.
This change is temporary, and a normal sense of taste should return eventually. Macmillan Cancer Support offer a fact sheet of tips to help people enjoy foods as normally as possible.
Vitamins with heavy metals such as copper, zinc, or chromium can be the cause of a metallic taste. Prenatal vitamins, iron, or calcium supplements can also result in the same problem.
The taste should go away as the body absorbs the vitamins, but it’s best to check the dosage to make sure the correct amount is taken.
Some women report a change in taste and smell in the early stages of their pregnancy. This is due to hormonal changes occurring in the body.
Along with a metallic taste, a change in cravings or a dislike for certain foods is also common for pregnant women. In this case, the metallic taste tends to go away with time.
People with dementia can sometimes experience taste changes like a metallic taste. Because the taste buds send signals to the brain, taste changes can occur if part of the brain is not working properly.
A metallic taste in the mouth can sometimes be a symptom of Guillain-Barré Syndrome, an autoimmune disease that affects the peripheral nervous system.
A 2003 review stated that this can be due to the dysfunction of small nerve fibers.
Some allergies cause sinus problems, which can then cause a metallic taste. However, there are some other allergens said to cause metallic taste. Tree pollen, tree nuts, and shellfish are among these.
Anyone who is unaware of any food allergies but has eaten or been exposed to these foods and experiences a metallic taste should let their doctor know.
Kidney failure is one of the more serious causes of dysgeusia. A metallic taste is also fairly common in people with diabetes, which can then lead to kidney failure.
About 30 percent of patients with type 1 diabetes and 10 to 40 percent of patients with type 2 diabetes will eventually have kidney failure, according to the National Kidney Foundation.
Waste buildup in the kidneys can result in bad breath or loss of appetite, causing a metallic taste.
When to see a doctor
If someone receives medication for a cause of a metallic taste and it remains, it could be a sign of a more serious problem. Also, if anyone has had a recent sinus or dental problem or has any of the pre-existing conditions mentioned above but the metallic taste remains, it’s best to see a doctor right away.
A metallic taste can cause loss of appetite. This can lead to weight loss, poor nutrition, depression, and even a weakened immune system if not treated.
For seniors, an untreated metallic taste could also be a sign of a central nervous disorder, such as Alzheimer’s disease or Parkinson’s disease.