Ketones

What are ketones?

Ketones, or ketone bodies, are acids your body makes when it’s using fat instead of glucose for energy. Your body gets most of its energy from glucose, a sugar that mainly comes from carbohydrates in your diet. If you don’t get enough energy from glucose, your body breaks down fats for energy instead. The breakdown releases ketones that travel through your bloodstream. The ketones fuel your body’s tissues and eventually exit in your urine (pee).

It’s normal (and safe) to have some ketones in your blood because it’s normal for your body to use its backup energy source — fats — when there’s not enough usable glucose.

But too many ketones can make your blood acidic and toxic. This is called ketoacidosis. If you have diabetes, too many ketones can cause diabetes-related ketoacidosis (DKA). DKA is life-threatening without treatment. It’s crucial to get treated right away.

What do ketones do in your body?

Ketones fuel your brain and body in the absence of glucose, your body’s primary energy source. Think of ketones as your backup energy reserve when the main source is depleted, low or unusable.

Typically, your body breaks down food into glucose. A hormone called insulin helps your cells use glucose as an energy source or store it for when you need it later.

Your body will switch to ketosis if you’re not getting enough carbohydrates. During ketosis, your body breaks down fats for energy, releasing ketones. The ketones energize cells and tissue so your body can keep working. Ketosis is a normal process. For example, your body can go into ketosis (and make more ketones) when:

• You’re asleep.
• You’re fasting.
• You’re exercising.
• You’re on the keto diet.

People on the keto diet purposely cut back on carbs and eat more fatty foods so their bodies will burn more fat. Inducing ketosis with the keto diet may provide benefits depending on your health. But you should always speak with a healthcare provider before trying this diet. It causes major changes to your body and isn’t for everyone. Also, the keto diet is very restrictive, so it can be difficult to stick to for extended periods of time.

Where are ketones located?

Ketosis occurs in your liver. Your liver releases the ketones into your bloodstream, where they travel throughout your body, providing energy. Once they’ve done their job, you pee them out.

What are the common conditions and disorders associated with ketones?

Understanding what ketones do and keeping track of ketone levels is especially important if you have diabetes — Type 1 diabetes, in particular. Type 1 diabetes is a condition that prevents your body from making insulin. Insulin is the hormone that helps your body use glucose for energy.

Problems with insulin cause your blood sugar levels to rise (hyperglycemia) and can cause too many ketones to build up in your blood. This can lead to diabetes-related ketoacidosis (DKA). DKA is more common in people with Type 1 diabetes but can happen with Type 2 diabetes, too.

People with alcohol use disorder are at risk of alcoholic ketoacidosis. People with a history of heavy drinking may develop dangerously high levels of ketones. This usually happens after binge drinking and vomiting, which prevents you from getting enough nutrition. Like DKA, alcohol-related ketoacidosis is a medical emergency that requires immediate treatment.

What are the symptoms of high ketones?

Call your provider immediately or visit the ER if you have diabetes and notice symptoms of high ketones.

Early symptoms are similar to the symptoms of high blood sugar and include:

• Having to pee more than usual (frequent urination).
• Feeling extremely thirsty.
• Dry mouth and dehydration.
• Dry skin.
• Headache.

Without treatment, DKA can progress fast (within 24 hours or even less). Symptoms include:

• Nausea and vomiting.
• Fatigue (feeling tired and weak even with rest).
• Stomach pain.
• Shortness of breath.
• Confusion.
• Fruity-smelling breath (sometimes called “keto breath”).

What tests check ketone levels?

You can get tests to check ketone levels in a pharmacy or order them online. If you’re at risk of DKA, ask your healthcare provider about the type of test they recommend based on your health situation. Have tests handy so you can act fast if you notice symptoms of DKA.

Blood tests

You can get a blood test in your provider’s office or buy a kit to use at home. The at-home kits usually involve a finger prick. You apply a blood drop to a testing strip that’s read by a meter. The meter will tell you what your current ketone levels are.

Some glucose monitors (glucometers) test both blood sugar and ketone levels. If you have one, you won’t need to buy a separate test.

Urine tests

Urine tests usually involve a dip-and-read test strip. You pee into a container, dip the stick into the pee and wait for it to change color. Urine tests have a chart showing a color range for different levels. Compare your test strip to the chart.

Unlike a blood test, urine tests can’t tell you your body’s current ketone levels, but they can tell you what your ketone levels were within the last few hours.

Breathalyzer tests

Some people on the keto diet use handheld breathalyzers to check their ketone levels. These breathalyzers detect acetone, a type of ketone. But this technology is still new. Researchers need to study them more before they’re considered reliable and accurate tests.

People at risk for DKA should never rely on a breathalyzer to check their ketones.

What do ketone test results mean?

Knowing your ketone levels can alert you that you’re at risk of DKA and need to act fast to get your ketone levels down. Ketone values vary depending on the test you’re taking. Also, what’s considered a normal or high ketone level can vary from person to person.

The chart below provides general guidance on what blood ketone levels mean for your DKA risk and what actions you need to take.

When should I check my ketone levels?

Your healthcare provider will advise you on when or how often you should check your levels if you have diabetes. They may advise you to check when:

• You have symptoms of DKA.
• You’re sick or injured.
• You’ve missed one or more insulin injections.
• Your blood sugar levels are higher than 240 milligrams/deciliter (mg/dl).
• You’re pregnant. (Insulin levels can be more challenging to manage during pregnancy. If you have diabetes, you may need to take extra care to monitor your insulin and ketones during pregnancy).

What happens if ketone levels are high?

High ketone levels can make your blood too acidic and toxic. This is what happens with ketoacidosis. Diabetes-related ketoacidosis (DKA) is the most common type of ketoacidosis.

What are the common treatments for high ketones?

Treatment depends on how high your levels are. Your healthcare provider may guide you on steps to lower your levels at home before they get dangerously high. They may advise you on:

• How much insulin to take.
• How much food and water to consume (and what types of food).
• What level of activity is safe.
• How often you should check your blood sugar and ketone levels.
• What blood sugar and ketone levels require a visit to the doctor (or the ER).

Treatments in the hospital include IV fluids and insulin to reduce your ketone levels.

How can I keep my ketone levels in a safe range?

Work with your healthcare provider to take steps to prevent DKA if you’re considered high-risk.

• Maintain a routine that keeps your levels in check. Stick to a meal plan and insulin regimen that keeps your blood sugar levels in a safe place. This reduces your risk of high ketones. Speak to your diabetes healthcare provider to determine what’s safe.
• If you wear an insulin pump, talk to your diabetes care team about how to prevent DKA. Understanding how your pump delivers insulin, knowing how to identify a pump failure, and having a backup plan for emergencies can help to decrease your risk for DKA while using an insulin pump.
• Know your levels (and when to test). Know what ketone levels are considered normal for you and when to take steps to lower them. Talk to your provider about when you may need to perform ketone tests (for example, if you’re injured or have an infection).
• Be prepared. Have ketone test kits handy in case you’re noticing symptoms of DKA. Work with your healthcare provider to have a plan if your ketones are high. Knowing when to call your provider or when to get to the ER fast is crucial.

A note from Cleveland Clinic

Most of the time, ketones work behind the scenes, keeping your body fueled when there’s not enough usable glucose. They become especially important if your levels get high and you have Type 1 diabetes. Talk to your healthcare provider about steps to take if your levels get high. Have a plan in place to keep your ketones at a safe level to prevent complications like DKA.