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.

How diabetes can affect breath

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.

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

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.

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