Why is there a weird taste in your mouth like you’ve been sucking on old pennies? In the medical community, this is referred to as dysgeusia (also called parageusia), which can develop suddenly or over a period of time. It is characterized by an unusual taste in the mouth that is typically metallic or rancid.

Dysgeusia can develop for several reasons. Most of the time, the cause is benign, and the unpleasant taste will go away all on its own. In some cases, though, the metallic tang is a symptom of a more serious underlying disease or disorder that may require treatment, especially when it accompanies other symptoms.

Here are 13 possible reasons for that funky taste in your mouth…

You’re on Medication

Certain medications can cause dysgeusia. Some contain metals that are excreted through saliva. Others decrease saliva production or interfere with signals sent to the brain from the taste buds.

Drugs known to cause a metallic taste in the mouth include lithium (a psychiatric medication), allopurinol (for kidney stones and gout), and certain blood pressure medications and antibiotics.

You Take OTC Drugs or Vitamins

Some over-the-counter cold medications can leave a metallic taste in the mouth (e.g., zinc syrups and lozenges), as can multivitamins that contain metals such as zinc, copper, and chromium.

Prenatal vitamins and iron or calcium supplements can have the same effect. Normally, the taste will subside as the vitamin or supplement is processed. If not, then your dosage could be too high.

Your Oral Hygiene Isn’t Great

Not brushing and flossing your teeth regularly can lead to an inflammation of the gums called gingivitis. Gingivitis increases your risk of developing serious gum infections like periodontitis.

Gum and tooth infections – apart from potentially causing health problems – can decrease blood flow to the tongue, reducing saliva production and blocking taste buds. This can cause dysgeusia.

Your Sinuses Are Infected

Sinus infection symptoms such as facial pain, coughing, headaches, and a stuffy nose are no fun. The nasal congestion that occurs with sinusitis often can leave a strange, metallic taste in your mouth.

When salivary flow is impaired due to swelling and blockage, this can affect the taste buds. Also, a distorted sense of smell can have an impact on your sense of taste, as the two are closely related.

You’ve Experienced Head Trauma

If you incurred an injury to your brain, skull, or scalp at some point, say from a severe car accident or a sports injury, that could be the reason behind your dysgeusia.

Head traumas can injure cranial nerves, including those that are responsible for controlling your sense of taste and smell. When this occurs, there may be perception changes.

You Have a Systemic Disease

A variety of systemic diseases can cause a metallic taste inside the mouth. These include hyperparathyroidism, diabetes, renal failure, amyloidosis, sarcoidosis, Sjogren’s syndrome, and cancer.

Sometimes, it’s not the disease but the treatments that cause dysgeusia. Chemotherapy, for example, is known to alter the sense of taste when anti-cancer drugs get into blood and saliva.

You Have a Nervous System Disorder

In some individuals, taste disturbances result from neurological diseases or disorders that affect the central nervous system (CNS), such as multiple sclerosis and Bell’s palsy.

The CNS sends signals to the rest of the body, including signals relating to taste. A central nervous system disorder can alter these messages, causing a metallic taste in the mouth.

You Are Pregnant

Could you be pregnant? In addition to suddenly disliking certain foods, some women report an unusual metal taste in their mouth during pregnancy, particularly in the early stages.

The cause of dysgeusia during pregnancy is unknown, but experts believe it results from hormonal changes and/or the heightened sense of smell that develops in some pregnant women.

You Have Acid Reflux

With acid reflux, a burning pain or discomfort is felt in the center of the chest (heartburn) due to the regurgitation of gastric acid intended to break down food and protect against pathogens.

This strong digestive stomach fluid regurgitates into the esophagus. If it happens to reach the back of your mouth, then your taste receptors may be damaged and you may develop dysgeusia.

You Smoke

There are many good reasons to give up cigarette smoking. Here’s another one: Smoking alters your sense of taste, and the chemicals that you inhale can leave a metallic taste in your mouth.

Dysgeusia from smoking occurs because the harmful chemicals inhaled damage your taste buds. They also prevent them from regenerating, which can result in permanent dulling.

You Inhaled Toxic Chemicals

It’s not only cigarette smoking that can affect your taste buds adversely and cause dysgeusia; long-term exposure to various environmental chemicals can alter your taste, too.

Over time, chemicals that may produce an unpleasant metal-like taste in the mouth include gasoline, hydrazine, benzene, lacquers, chromates, cobalt, and rubber dust.

You Ate Bad Fish

Consuming fish that is spoiled or rotten can make a person very ill. It can also bring about dysgeusia, although the unfavorable metallic taste is usually temporary and dissipates within a few days.

Some types of spoiled fish – mackerel, tuna, herring, mahi-mahi, sardine, bonito, etc. – are more likely to have this effect when consumed. This is known as scombroid food poisoning.

You Have Food Allergies

For some individuals, dysgeusia is a symptom of food allergies. If you recently ate something you don’t normally eat, then that metallic taste you are experiencing may be an allergic reaction.

There have been reports of people experiencing dysgeusia after eating tree nuts, shellfish, and various other foods. Consult a medical professional if you suspect such an allergy.