Ketones are substances produced by the liver when cells don't get enough glucose (blood sugar) for fuel. When ketone levels are high in your urine, it is known as ketonuria. This is a sign of a potentially serious complication of diabetes known as diabetic ketoacidosis (DKA).

If left untreated, DKA can damage vital organs and even lead to death. This is why it is important to know the signs of ketonuria and when to check your ketone levels with a urine or blood test.

This article explains the signs and symptoms of ketones in urine. It will also discuss what conditions can trigger ketonuria, possible complications, and when to seek emergency care for ketoacidosis.

Verywell / Katie Kerpel

What Is Ketonuria?

Ketones are essential to a normal healthy body. They are used as fuel when insulin levels are low and your body does not have enough glucose to drive metabolism (the conversion of calories to energy).

While glucose is the body's main fuel source, the body will turn to fat when glucose stores have been depleted. Ketones are the body's alternative fuel source, created in the liver by the breakdown of fat.

It is normal to have a certain amount of ketones in your blood, such as when you are dieting and are in a fasting state during sleep. But, when levels are abnormally elevated, you are said to have ketonuria, a potentially serious health concern.

What Are the Symptoms of Ketonuria?

Ketonuria tends to occur when a person is hypoglycemic (has low blood sugar). Common symptoms of ketonuria include:

Ketonuria symptoms are sometimes the first clue that a person has diabetes. It is for this reason that you should see your healthcare provider if you have symptoms like these so that your ketone level can be checked and other tests can be performed to see if you have diabetes.

What Conditions Cause Ketones in Urine?

Ketonuria is most common in people with diabetes, particularly type 1 diabetes. With diabetes, the body either doesn't produce enough insulin (the hormone that regulates the production and storage of glucose) or doesn’t use insulin properly.

So, if you have ketones in your urine, it is an indication of an insulin problem.

But, there are other reasons why you might experience ketonuria, namely if the body's glucose stores are severely depleted. Reasons for this might include:

  • Long-term vomiting or diarrhea
  • Excessive exercise
  • Restrictive diets
  • Eating disorders
  • Starvation
  • Alcohol use disorder
  • Pregnancy and breastfeeding

Severe infections, including COVID-19, can also lead to ketonuria.

What Are Complications of Ketonuria?

If you have uncontrolled diabetes, ketone levels can skyrocket. High levels can cause acids to rapidly accumulate in the blood, leading to ketoacidosis. This is damaging to your vital organs and can even lead to death if not treated appropriately.

In people with diabetes, the condition is known as diabetic ketoacidosis (DKA). In those without, it is referred to as non-diabetic ketoacidosis (non-DKA).

Complications of ketoacidosis include:

  • Acute kidney failure: This is a serious but generally reversible condition in which the kidneys stop filtering blood.
  • Pulmonary edema: This is where fluid builds up in the lungs, causing severe breathing problems.
  • Cerebral edema: This is a medical emergency where the brain swells and doesn't get enough oxygen, leading to seizures, loss of consciousness, and other symptoms.
  • Cardiac arrest: This is a life-threatening situation in which the heart stops beating.

When Should I See a Healthcare Provider for Ketonuria?

Ketonuria can be detected with modern glucometers that can detect not only your blood sugar levels but your ketone levels as well.

Ketone levels are measured in millimoles per liter of blood (mmol/L) and are considered normal when they are below 1.5 mmol/L.

A reading of above 1.6 mmol/L means that you are at increased risk of ketoacidosis and need to see your healthcare provider immediately.

When to Call 911

Call 911 or rush to your nearest emergency if you have diabetes and experience the following:

  • Blood sugar readings that remain at or above 300 mg/dL
  • Fruity breath
  • Vomiting
  • Trouble breathing
  • Other signs and symptoms of DKA


Having some ketones in your urine is normal, but high levels (known as ketonuria) can be harmful to the body and lead to a potentially life-threatening condition called ketoacidosis. Ketones are chemicals produced by the liver that increase whenever glucose (blood sugar) levels are low.

Ketonuria is a possible complication of diabetes, particularly type 1 diarrhea, but can also occur with long-term vomiting or diarrhea, pregnancy, eating disorders, and infections. Symptoms include frequent urination, fruity breath, extreme fatigue, nausea or vomiting, and breathing difficulty.

A Word From Verywell

If you have diabetes, the best way to avoid ketonuria and ketoacidosis is to manage your blood sugar. If you have trouble doing so, speak with your healthcare provider. It may be that your treatment needs adjustment or you need to change your diet or certain lifestyle practices.

If you are at risk of diabetic ketoacidosis, consider investing in a glucometer with a built-in ketone meter. While urine test strips are available for at-home testing of ketone, blood readings tend to be far more accurate.

Frequently Asked Questions

  • Are ketones bad?

    It depends. In people with diabetes, the presence of ketones often indicates a problem, such as diabetic ketoacidosis. High levels may also indicate other conditions in those who don't have diabetes, such as pregnancy, restrictive dieting, or an infection.

  • Can dehydration cause ketones in urine?

    Not typically. Ketones show up when the body burns fat for energy. Starvation can cause high amounts of ketones, but dehydration does not.

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