Health and Beauty Tips, Skin Care

Why does my breath smell like acetone?

People often associate strong smelling breath with the food someone has eaten or poor dental hygiene. But it may reveal much more than that.

If a person’s breath smells like acetone or nail polish remover, it could indicate health conditions, including diabetes.

The way a person’s breath smells can be an indicator of their overall health. This article explores why a person’s breath might smell like acetone and what this might mean about their health.

How diabetes can affect breath

Woman checking how her breath smells by holding her hand in front of her mouth.

The smell of a person’s breath can indicate different things about their health.

Diabetes can affect the way a person’s breath smells and can cause bad breath, or halitosis. In a 2009 study, researchers found that analyzing a person’s breath helped to identify prediabetes when diabetes is in its early stages.

There are two conditions associated with diabetes that can cause bad breath: gum disease and a high ketone level.

The proper name for gum diseases in periodontal disease, and its forms include:

Diabetes can be associated with an increased risk of gum disease, which may cause a person’s breath to smell bad. However, gum disease does not cause a person’s breath to smell like acetone.

If a person has diabetes and their breath smells like acetone, this is usually caused by high levels of ketones in the blood.

Diabetes and acetone breath

When diabetes is not managed well, the body does not make enough insulin to break down glucose in the blood. This means that the body’s cells do not receive enough glucose to use as energy.

When the body cannot get its energy from sugar, it switches to burning fat for fuel instead. The process of breaking down fat to use as energy releases by-products called ketones.

Ketone bodies include acetone. Acetone is the same substance that is used in nail varnish remover and is distinguished by its fruity smell.

When a person with diabetes has breath that smells of acetone, it is because there are high levels of ketones in their blood.

Understanding ketones and acetone

Red, pink, and peach colored nail polish bottles on white background.

Nail polish and paint thinner contain acetone. It can occur naturally in the human body.

Acetone is one of the ketone bodies contained in ketones. These are released when the liver breaks down fatty acids for energy, in a process known as ketosis.

The ketones that are released into the blood are used by the body for fuel. Ketones that are not used for fuel are passed out of the body, mainly through the urine. Acetone is expelled when a person breathes out, which is why it can cause sweet-smelling breath.

As well as occurring naturally in the human body, acetone is found in:

  • paint thinners
  • nail polish
  • plastic manufacturing processes

Ketosis vs. diabetic ketoacidosis

Ketosis is not usually harmful, as long as the levels of ketones in the blood do not become too high. However, when a person has diabetes that is not well-managed, the ketone levels can rise too much.

Diabetic ketoacidosis or DKA is when ketone levels reach unhealthy levels. This condition is dangerous as the blood can become acidic and affect how other organs in the body function.

DKA can develop in less than 24 hours and is most common in people with type 1 diabetes. It can also affect people with type 2 diabetes if they have missed a dose of insulin or have been unwell.

Both ketosis and DKA can cause breath to smell like acetone, but the smell is likely to be less noticeable with ketosis.

If a person’s breath smells strongly of acetone or very fruity, this can indicate DKA. Other symptoms of DKA include:

passing urine more often than usual

  • nausea
  • vomiting
  • abdominal pain
  • high blood sugar levels
  • breathing difficulties
  • feeling confused

A person experiencing symptoms of DKA should seek medical assistance immediately.

Other causes of acetone breath

Diabetes is not the only condition linked to breath that smells of acetone. Two other causes are:

A ketogenic diet

Ketogenic diet foods laid out, including almond nuts, avocados, eggs, dairy, and blueberries.

The ketogenic diet is a type of low-cabohydrate diet that may cause acetone breath.

Ketosis is a metabolic state a person may try to induce by following a ketogenic diet if they are trying to lose weight. This can cause people to have acetone-smelling breath.

The ketogenic diet involves eating a diet high in fats, a moderate amount of protein, and with very few carbohydrates. Doing so forces the body to break down fats for energy, rather than carbohydrates.

A 2002 study found that an acetone smell on the breath was a clear indicator that the body of a person following a ketogenic diet was in a state of ketosis.

While a ketogenic diet may be appealing as a way to lose weight, it is important to be aware of its side effects. These include:

  • loss of salts
  • flu-like symptoms
  • fatigue
  • changes in bowel movements
  • bad breath
  • cramps in the legs


One possible complication of alcoholism is that a person may not eat enough. Long-term alcohol abuse and starvation are known to cause alcoholic ketoacidosis.

As with DKA, alcoholic ketoacidosis can cause a person’s breath to smell of acetone. Other symptoms of alcoholic ketoacidosis include:

  • nausea
  • vomiting
  • abdominal pain

When to see a doctor

When a person with diabetes detects a faint smell of acetone on their breath, they should ensure they are following their care plan closely. Usually, this involves taking insulin to regulate their blood sugar and bring the body out of ketosis.

If a person with diabetes notices their breath smells strongly of acetone or they experience other symptoms of DKA, they should see a doctor straightaway.

If a person notices a strong smell of acetone on their breath and does not already have a diagnosis of diabetes, they should also talk to a doctor. The doctor can help determine the cause of the smell and how to deal with it.

3 thoughts on “Why does my breath smell like acetone?”

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