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Was it something you ate at lunch, or is your body telling you something? Bad breath (aka halitosis) may be a symptom of underlying health concerns.

For example, breath that smells of ammonia is commonly associated with kidney disease. Breath that smells of rotting fruit? A possible sign of anorexia nervosa.

Other health conditions such as lung cancer, liver disease, cystic fibrosis, and asthma may also affect breath odor.

Many people with diabetes frequently experience breath that has a fruity, sweet odor or a chemical smell. In fact, it’s so common that infrared breath analyzers can detect prediabetes or early-stage diabetes.

There are two distinct reasons for bad breath if you have diabetes:

  1. Periodontal disease
  2. Ketoacidosis

Here’s a rundown of why your breath might be less than fresh.

Simply put, periodontal diseases are inflammatory gum diseases.

They include:

  • mild periodontitis
  • advanced periodontitis
  • gingivitis

One in three people with diabetes will experience some form of gum disease. And complications of diabetes, such as heart disease and stroke, may be linked to periodontal disease.

Bacteria = bad breath = ew

Diabetes raises your glucose levels, encouraging bacteria growth, inflammation, infection, and — you guessed it — bad breath.

Gum disease occurs when bacteria attacks your teeth and tissue.

Aside from bad breath, other symptoms of gum disease include:

  • bleeding gums
  • sensitive teeth
  • receding gums
  • red, tender gums
  • pain when flossing or brushing

Diabetes can affect your body’s ability to circulate blood. When your gums and teeth don’t get enough blood, they weaken and are more likely to become inflamed and infected.

When your body can’t produce insulin, your cells don’t get enough glucose to function. To make up for this, your body starts burning fat, which produces ketones (a process called ketosis).

High ketone levels lead to breath that smells of acetone (yup — the chemical in nail polish remover).

If you’ve ever tried a low-carb, high-protein diet, you may have experienced this, too, though not to the same degree as in diabetic ketoacidosis. More on that later.


When your ketone levels are off the charts, you’re at risk of developing diabetic ketoacidosis (DKA). DKA usually affects people with type 1 diabetes when blood sugar is left uncontrolled.

The three main causes of elevated ketones are:

  • too little insulin
  • too little food
  • low blood glucose

Symptoms of DKA include:

  • frequent urination
  • dry mouth and thirst
  • sickly-sweet, fruity breath
  • high blood glucose levels
  • difficulty breathing
  • confusion
  • abdominal pain, vomiting, cramping
  • dry, flushed skin
  • exhaustion

If you have these symptoms, you should get help immediately. DKA is a dangerous and potentially life-threatening condition.

Metformin is a diabetes medication that helps control blood sugar levels in adults with type 2 diabetes. Those who take metformin often note its fishy aftertaste. Eau de saumon? No, thanks.

If you think your bad breath is linked to metformin, have a chat with your doctor, who can help you find an alternative approach.

According to the CDC’s Division of Oral Health (DOH), 46 percent of U.S. adults have some form of gum disease. In fact, gum diseases are the most common diseases on the planet! (So you’re definitely not alone.)

But even though gum disease is common, it can develop into a more serious issue if left untreated. The first steps toward better oral health are to take dental hygiene seriously and manage your diabetes.

That means:

  • Brush your teeth at least twice a day.
  • Floss daily.
  • Drink water and keep your mouth moist (everyone’s favorite word).
  • Get a tongue scraper, which gently removes surface bacteria.
  • Keep your blood sugar in your target range.
  • Don’t skip the dentist.

Some other healthy-mouth habits to try:

  • Use sugar-free gum or mints to combat stanky breath and increase saliva.
  • Don’t smoke. (Like, in general. Just don’t smoke — ever. Diabetes or no diabetes.)

If your breath is getting particularly fragrant, check your blood sugar level. If it’s reading above 240 milligrams per deciliter, you should definitely check for ketones.

Thankfully, this can be done with a simple at-home urine test. You can buy affordable ketone and blood glucose tests online or at your local pharmacy. They even sync with your smartphone! Isn’t modern medicine the bomb?

If you’re in the throes of a cold or the flu, the American Diabetes Association recommends you test for ketones every 4 to 6 hours.

Go to the doctor right away if:

  • you have other DKA symptoms
  • your ketone levels are abnormally high
  • your breath has a strong acetone scent

Even if your bad breath isn’t reflective of your health, it can definitely hurt your confidence. If regular preventive methods don’t work for you, ask your doctor for alternative solutions.

Keto diet

A ketogenic diet is a low-carb, high-fat, and moderate-protein diet that can help improve glycemic control and help you lose some excess weight. A common nasty side effect is “keto breath.” This can be similar to what people with diabetes experience.

Keto may give you bad breath because your body is producing more ketones. They’re naturally released through saliva and urine, but an abundance of ketones can make your breath smell less than pleasant.

The good news is that keto breath usually improves once your body adjusts to the new diet. Try some sugar-free mints and brush your teeth often to ease the symptoms.

Alcoholic ketoacidosis

Alcoholic ketoacidosis (AKA) occurs in people with a history of binge-drinking behavior. Many develop AKA after long periods of alcohol dependency.

Basically, when you drink alcohol, your pancreas may briefly stop producing insulin. Insulin allows your body’s cells to consume glucose as energy. Your body will start burning fat for energy, increasing the production of ketones.

This condition can be life-threatening. It’s often associated with electrolyte disorders and serious heart issues such as cardiac arrhythmias. In some cases, AKA can be misdiagnosed as DKA.

It’s super important to seek medical help if you experience the following:

  • chronic fatigue
  • abdominal pain
  • slow movement
  • loss of appetite
  • irregular, deep, and rapid breathing
  • decreased alertness
  • signs of dehydration (such as thirst and lightheadedness)
  • nausea or vomiting

Bottom line

Sometimes a cigar is just a cigar. Bad breath can really just be bad breath. But if you have diabetes, take note of what your breath may be telling you.

Monitor your blood sugar and check your ketone levels to make sure your bad breath isn’t a sign of DKA. With prevention and care, your minty-fresh breath will be back in no time.

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