Everyone gets bad breath from time to time. Foods like onions or garlic or poor dental habits cause a strong odor in your mouth, which often gets better with simple lifestyle changes. But sometimes, bad breath is more complex and the symptom of a serious health condition.
If your breath smells like acetone -- the same fruity scent as nail polish remover -- it may be a sign of high levels of ketones (acids your liver makes) in your blood. It’s a problem mainly of type 1 diabetes but also can happen with type 2 if you get a serious condition called diabetic ketoacidosis (DKA). And it can happen for a few reasons not related to diabetes, including keto diets, fasting, and heavy drinking.
Diabetes and Acetone
Diabetes happens when your blood glucose (blood sugar), a key energy source from food, is too high. Normally, glucose gets into your cells thanks to a hormone from the pancreas called insulin. With diabetes, your body doesn’t make enough, or any, insulin or doesn’t use it well. Glucose then lingers in your blood and can’t get into your cells.
When your body can’t get energy from glucose, it burns fat in its place. The fat-burning process creates a buildup of acids in your blood called ketones, which leads to DKA if untreated. Fruity-smelling breath is a sign of high levels of ketones in someone who already has diabetes. It’s also one of the first symptoms that doctors look for when they check for DKA.
There are other symptoms of DKA besides fruity-scented breath, and they happen quickly; at times, within 24 hours. They’re also among the signs that you could have diabetes. You may notice that you’re:
- Thirsty and pee a lot
- Sick to your stomach and throw up
- Tired or weak
- Short of breath
- Losing weight quickly (newly diagnosed type 1 diabetes)
- Not sweating
It can also happen if you miss or don’t take your insulin.
When to Call Your Doctor
If you have diabetes and smell acetone on your breath, make sure to follow your doctor’s treatment plan. Most of the time, this means taking insulin, a medicine to control your blood sugar and stop ketosis from happening.
If you’re following your treatment plan and your ketone level is moderate or high, call your doctor right away for help. You should also contact your doctor if you don’t have diabetes and are worried about a lasting acetone scent.
DKA can be an emergency. You need medical care right away if:
- You have more than one symptom of DKA
- You can’t reach your doctor
- Your blood sugar is staying above 300 mg/dL
Other Causes of Acetone Breath
While diabetes is the main reason people get acetone breath, it can also happen because of these other things:
Keto diet and fasting: Changes to your diet can create acetone-scented breath. On a ketogenic, or keto, diet (high fat, moderate protein, very low carb) or on some fasting plans, your body uses fat instead of carbohydrates for energy. This shift causes a major spike in ketones, the source of acetone breath. Some people on a keto diet even measure their ketone levels with at-home tests to make sure they’re staying on track. Sweet-smelling breath may be a short-term side effect of this type of diet but could last longer.
Alcoholic ketoacidosis: Heavy drinking can cause a buildup of ketones in your blood, an illness called alcoholic ketoacidosis. It usually happens if you drink large amounts of alcohol every day, along with throwing up and not eating. It can be tough for doctors to spot alcoholic ketoacidosis because its symptoms -- throwing up, and stomach sickness and pain -- are like those of other conditions linked to alcoholism. The illness can be deadly if you have a severe alcohol addiction but usually gets better quickly if treated right away.