Why Does Your Breath Smell Fruity?

Think you know what bad breath smells like? Maybe it smells rotten, sour or just … pungent.

But what if you open your mouth and send out a cloud of fruit salad? What’s that about?

“Oftentimes, we think of ‘bad breath’ as a sign of poor oral hygiene,” says registered dietitian Melissa Matteo, RD, LD. “But fruity breath or very sweet breath usually indicates something going on outside of your mouth.”

If you have diabetes, seek emergency care for fruity breath, as it can be a sign of a life-threatening complication.

What causes fruity breath?

Fruity breath can smell unpleasantly sweet, like overripe fruit or even nail polish remover. That distinctive scent can be a sign that your body is burning fat for energy.

Let’s break that down.

Typically, your body uses glucose (sugar) as its main fuel source. But if glucose isn’t available, it starts breaking down fat. That’s a state called ketosis.

“When you’re in ketosis, your body releases acids called ketones. And ketones can give your breath a sweet or fruity smell,” Matteo explains. “That’s why you might hear sweet-smelling breath called ‘keto breath.’”

There are two main reasons it happens.

Your diet

Sure, what you eat can affect your breath in the moment. A cup of coffee, a tuna salad sandwich or an everything bagel are obvious culprits.

But restricting carbohydrates in your diet over time can trigger ketosis and bring on fruity breath. That typically happens if you:

• Follow a keto diet
• Eat a lot of extra protein
• Are fasting or not eating enough
• Engage in very intense exercise

“Ketosis typically isn’t dangerous for most people,” Matteo says. “But it’s not safe for everyone, especially if you’re living with a chronic condition.”

Always talk with a healthcare provider before starting a keto diet or any eating plan that severely restricts any food or food group.

Diabetes-related ketoacidosis (DKA)

Here’s where fruity breath gets serious.

If you have diabetes and your breath gives off a fruity or sweet smell, it can be a sign of a serious medical emergency called diabetes-related ketoacidosis (DKA).

“DKA happens when your body doesn’t have enough insulin to move glucose into your cells,” Matteo explains. “For people with diabetes, that can cause ketones to build up to dangerous levels and make your blood acidic.”

DKA is more likely to happen in people with Type 1 diabetes, but it can affect people with Type 2 diabetes, too. Without treatment, it’s fatal.

When to seek medical attention

Fruity breath demands prompt medical attention if you have diabetes — or if you have other symptoms of diabetes but haven’t been diagnosed. In fact, sweet-smelling breath may be one of the first clues of Type 1 diabetes.

Early signs of DKA can include extreme thirst, frequent peeing, intense hunger and dehydration. As DKA becomes more severe, you may notice fruity breath, as well as:

• Nausea or vomiting
• Abdominal pain
• Rapid, deep breathing
• Extreme tiredness or weakness
• Confusion or disorientation
• Decreased alertness or loss of consciousness

DKA can develop quickly — sometimes within 24 hours — and even faster if you’re vomiting.

“If you have symptoms of DKA, contact a healthcare provider immediately or go to the nearest emergency room,” Matteo stresses.

The bottom line? A change in your breath can sometimes offer a clue about what’s happening elsewhere in your body. If there’s no clear explanation for fruity breath — or it comes with other symptoms — don’t try to cover it up with a mint. Talk to a healthcare provider about what’s behind it.