A persistent metallic taste in your mouth is called parageusia. It can have a wide range of causes that may be temporary or long-lasting.

Many people experience a metallic taste in combination with fatigue and other symptoms. The cause of these symptoms can be anything from a minor issue like seasonal allergies to potentially serious conditions such as kidney failure.

Let’s take a look at some of the most common causes of fatigue and a metallic taste in your mouth as well as how they’re generally treated.

Here are some of the most common reasons why you may experience a metallic taste in your mouth and fatigue.

Hay fever

Hay fever, also known as allergic rhinitis, is an allergy to pollen, dust, or other allergens. It’s extremely common. According to the Centers for Disease Control and Prevention (CDC), 19.2 million people in the United States were diagnosed with hay fever between 2017 and 2018.

Hay fever can leave a metallic taste in your mouth due to inflamed nasal passages that disrupt your ability to taste. You may experience fatigue when dealing with allergies due to chemical changes in your body and disrupted sleep.

Other common symptoms include:

Sinus, upper respiratory, and ear infections

Infections that block your ability to smell can interfere with your ability to taste and may leave a metallic taste in your mouth. Infections also commonly cause tiredness while your body fights off the virus or bacteria.

Other symptoms can vary based on the type of infection, but may include:


COVID-19 is an illness caused by a strand of coronavirus discovered in late 2019. COVID-19 can cause a wide range of flu-like symptoms 2 to 14 days after exposure.

Common symptoms include:

Like other illnesses that impair your taste and smell, COVID-19 has the potential to leave a metallic taste in your mouth.

A case study published in May 2020 described a person in China whose initial symptom of COVID-19 was a loss of taste and smell.

The person described food she normally enjoyed as “bland and metallic.” A few days later, she developed a cough, tiredness, shortness of breath, and chest tightness before being admitted to intensive care.

COVID-19 testing

If you think you may have COVID-19, it’s a good idea to get tested as soon as possible. Call a doctor’s office to schedule a test, or go to a testing facility. Wear a mask until instructed to take it off.

Don’t go to a doctor’s office or hospital without first notifying the office. If you have COVID-19, you risk spreading it to others.

If you have serious symptoms like difficulty breathing, call 911 but tell the dispatcher you believe you may have COVID-19. This will allow responders to prepare and protect themselves.

Medication side effects

A wide variety of medications can lead to a metallic taste in your mouth as a side effect. These include:

Medications can have a long list of other side effects. Some of the most common include:

Cancer treatment

People undergoing chemotherapy commonly experience a metallic taste in their mouths. It’s estimated that 10 to 80 percent of people who undergo chemotherapy experience a metallic taste.

Other side effects of chemotherapy include:

  • fatigue
  • hair loss
  • gastrointestinal symptoms
  • anemia
  • easy bruising
  • mouth and throat sores or pain
  • weight changes
  • decreased focus and concentration
  • changes in mood


Many who are pregnant experience fatigue, nausea, and a metallic taste from fluctuating hormone levels. Symptoms are generally worse in the first trimester.


Some people with anxiety report experiencing a bad or metallic taste in their mouths. Anxiety stimulates the release of your body’s stress hormones, which may impact your sense of taste. It can also lead to a dry mouth, which might contribute to this bad taste.

Pine nut syndrome

Pine nut syndrome is a rare reaction to pine nuts that begins 12 to 48 hours after eating them. It causes a bitter metallic taste in your mouth that can last up to a month.

Vitamin B12 deficiency

Vitamin B12 deficiency can cause a range of symptoms that affect your nervous system and energy levels. Your body may stop producing an adequate amount of blood cells, which may lead to tiredness and a lack of energy. Your nerves might not function properly, and you might develop tinnitus or a metallic taste.

Kidney disease or kidney failure

Your kidneys filter out waste and excess water from your blood. When they’re not working properly, waste can build up and cause a variety of symptoms including a metallic taste and fatigue.

Usually, kidney disease doesn’t cause symptoms until it’s in the late stages. Late-stage kidney disease, also called kidney failure, can cause:

  • shortness of breath
  • swollen ankles, feet, or hands
  • weight loss
  • poor appetite
  • blood in urine
  • frequent urge to pee
  • muscle cramps
  • headaches

Kidney failure can be life-threatening. If you think you may be experiencing kidney failure, call 911 or go to the nearest emergency room.

Poor oral hygiene

Poor oral hygiene may cause a metallic taste in your mouth. However, if you’re also experiencing fatigue, it’s not the most likely cause.

Often, fatigue and a lingering metallic taste present themselves among other symptoms.

Metallic taste in mouth, nausea, fatigue, and headaches

If you’re also experiencing nausea and headaches, possible causes include:

  • pregnancy
  • medications
  • viral infections

Fatigue, metallic taste in mouth, and anxiety

Anxiety has the potential to lead to fatigue and a bad taste in your mouth. It may also exacerbate other conditions that may be the cause.

Metallic taste and flu symptoms

If you’re experiencing a metallic taste and flu symptoms, it may be a sign of:

  • allergies
  • sinus infection
  • common cold
  • COVID-19
  • respiratory infections

If you’re experiencing a metallic taste along with fatigue, it’s a good idea to see a doctor for a proper diagnosis. The cause is often not serious and may simply be allergies or a side effect of medication.

However, in some cases, it can be an early warning sign of a more serious problem, such as kidney failure or COVID-19.

A doctor will likely look at your medical history, perform a physical exam, and ask you about your symptoms. In some cases, this may be enough for them to identify the problem. However, they may also refer you to get a blood test if they suspect you may have a nutritional deficiency or if they suspect another underlying cause.

If a doctor thinks you may have COVID-19, they will likely test you to confirm the diagnosis.

Treatment for fatigue and a metallic taste in your mouth depends on the underlying cause.


Allergies are usually treated by making lifestyle changes to reduce contact with dust, mold, and other allergens. Nondrowsy antihistamines are available over the counter to help you manage your symptoms.

Viral infections

If you have a viral infection, such as a sinus infection or COVID-19, it’s important to stay hydrated and get plenty of rest to allow your body to recuperate. Nasal decongestants may help you improve your breathing. Ibuprofen and other anti-inflammatories may help with body aches and pains.

If you’re experiencing shortness of breath, a fever over 103 degrees, or pressure in your chest, you should seek medical attention.


If your medication is causing your symptoms, a doctor may recommend changing your dose or the medication.

Other treatments

Kidney damageSeek emergency medical attention.
Pine nut syndromeWait for symptoms to resolve and avoid pine nuts.
Vitamin B12 deficiencyTake supplements and foods high in vitamin B12.
AnxietyFind ways to manage the cause of your anxiety.
Poor oral healthGet regular dental checkups, brush your teeth twice per day, and floss daily.
ChemotherapyTreatment varies on a case-by-case basis.

A metallic taste paired with fatigue can have many potential causes. Some of these are relatively mild. However, in some cases, it can be a sign of a serious condition. If you’re experiencing fatigue and a metallic taste in your mouth, it’s a good idea to visit a doctor for a proper diagnosis.