Why High Blood Sugar Levels Can Cause a Metallic Taste in Your Mouth

If you have diabetes, you may notice a sweet or metallic taste in your mouth when your blood sugar levels get too high. This could be signaling a serious condition called diabetic ketoacidosis (DKA).

DKA occurs when your body is no longer able to burn carbohydrates for energy and burns fat instead. Although this condition is mostly linked with type 1 diabetes, it can rarely occur with type 2 diabetes as well, according to the American Diabetes Association (ADA).

Here are some causes of DKA and what to do if you suspect you’re experiencing this condition.

What Causes Diabetic Ketoacidosis?

To understand what causes DKA, it’s helpful to know how your body uses glucose, and particularly the role of insulin in this process.

When you eat carbs in foods like breads, pasta, and fruits, your digestive system breaks them down into glucose, a type of sugar, according to the ADA.

Glucose then enters the bloodstream, where it raises your blood sugar levels. In response, your body releases more of the hormone insulin, which helps shuttle glucose out of your blood and throughout the cells in your body to be used as energy.

However, if you have diabetes and eat too many carbohydrates or don’t give yourself enough insulin, the glucose in your bloodstream can build up. If this occurs, you can experience high blood sugar levels, or hyperglycemia, explains the ADA. Left untreated, hyperglycemia can lead to DKA in some people.

DKA is a serious condition that occurs when the body doesn’t have enough insulin to use glucose for energy. When your cells can’t use glucose for energy, they begin to burn fat instead, according to the ADA.

If your body starts breaking down fats, it will also produce ketones. Ketones can be used as fuel for the brain when glucose is not available, but they contain chemicals that can make your blood more acidic.

Your body can’t handle too many ketones, so it will try to flush them out through the urine. Eventually, however, if ketones continue to build up in the blood, DKA develops.

What Causes That Metallic Taste in the Mouth?

A by-product of ketones is a chemical called acetone, according to StatPearls. Your body gets rid of the acetone by breathing it out, which is why you may have a strange taste in your mouth.

Some people describe the taste and smell as fruity or sweet, while others say it’s metallic.

According to the ADA, other symptoms of DKA include:

• Thirst
• Dry mouth
• Frequent urination
• Nausea
• Trouble breathing
• Fatigue
• Confusion

How to Detect Diabetic Ketoacidosis

Talk to your healthcare provider about when you should test your ketone levels, since this can vary from person to person. The ADA says to check for the presence of ketones when blood sugar levels rise above 240 mg/dL.

You can check your ketones with a simple blood or urine test. Like your glucose tests, the urine test uses a test strip. If you do have ketone levels that are higher than normal, call your doctor right away.

The ADA also warns people not to work out when they’re experiencing high blood sugar and ketones, since exercising during this time might cause blood sugar levels to rise even more.

Who Experiences Diabetic Ketoacidosis?

Most people who experience DKA have type 1 diabetes. Occasionally, people with type 2 diabetes can develop it, too, says Susan Spratt, MD, an endocrinologist and associate professor of medicine at the Duke University School of Medicine in Durham, North Carolina.

There’s a higher risk of people with type 2 diabetes developing DKA if they take a diabetes medication called an SGLT2 inhibitor, like empagliflozin (Jardiance) or dapagliflozin (Farxiga). In these cases, the blood sugar is commonly normal or mildly elevated, otherwise known as euglycemic DKA.

Diagnosing and Treating DKA

If you suspect that you have DKA, use your meter to check whether your blood sugar is high. An over-the-counter urine test or blood test can also reveal the presence of ketones.

While there’s a chance you can bring your blood sugar back down on your own with more insulin, Dr. Spratt says you should go to the emergency room if you’re experiencing DKA symptoms including nausea, vomiting, abdominal pain, and extreme fatigue.

At the emergency room, the doctors should treat you with intravenous fluids (an electrolyte solution) and check your potassium levels, says Spratt. “You can get very depleted in potassium when your body is acidotic,” she says.

The goal of treating DKA is to reverse the high blood sugar levels with insulin as well as to replace any fluids you might have lost if you’ve been vomiting, according to MedlinePlus.

Doctors will also search for any underlying infections that might have caused the DKA in the first place. The good news is that most people respond to treatment within about a day.

If you’re experiencing symptoms of DKA, it’s important to seek treatment right away. Possible complications, according to MedlinePlus, include cardiac arrest, kidney failure, and a buildup of fluid in the brain. If left untreated for too long, DKA can lead to death.