After the blood test or urine test has been performed, the test results will be compared to a range of values. Urine ketone test results are revealed through color changes on the test strip. The amount of ketones present in the urine is expressed either quantitatively as milligrams per deciliter (mg/dL) or in descriptive terms, such as negative, trace, small, moderate or large.

Most urine ketone test values can be read as:

Blood ketone test results are expressed on the glucose meter as millimoles per liter (mmol/L). Most blood ketone test values can be read as:

To be prepared, patients should discuss ketone testing with their physician ahead of time. A physician can recommend what actions to take for different ketone levels.

A trace or small amount of ketones may mean that ketones are beginning to build up (ketosis). These waste products should not be allowed to build up because high amounts of ketones can lead to diabetic coma and possibly be life-threatening. People with diabetes should drink a large amount of water and, if previously recommended by a physician, take an extra dose of insulin. The patient should perform blood tests for glucose every three to four hours, checking for ketones if glucose is over their physician-recommended range (usually over 240 mg/dL for type 1 diabetes and over 300 mg/dL for other forms of diabetes).

In a person with diabetes, moderate or high amounts of ketones may be a sign of uncontrolled glucose. High ketone levels may not be a concern when glucose is within a normal range, such as with nondiabetic people trying to lose weight. However, a combination of high ketones and high glucose (hyperglycemia) can lead to diabetic ketoacidosis. Moderate or large amounts of ketones may also be found when a person is starving, has anorexia, is on a low-carbohydrate diet or has alcoholic ketoacidosis.

People with diabetes may find moderate or high amounts of ketones when they do not have enough insulin to use glucose for energy or when they have not had enough food. Patients who have a moderate or large amount of ketones should check their glucose level and call their physician immediately. The physician can recommend the actions needed to lower the ketone levels and prevent diabetic ketoacidosis. The patient may need to take an extra dose of insulin and drink water to avoid dehydration and flush out the ketones. People are advised to refrain from exercise when they have high levels of ketones and high levels of glucose. Additional glucose and ketone tests may also be required.

By recognizing the warning signs and following the physician-recommended steps, most people can prevent ketones from reaching dangerous levels. When ketones do reach dangerous levels, patients must receive immediate emergency treatment in a hospital. Patients with diabetic ketoacidosis are normally treated with an intravenous (I.V.) drip of insulin and fluids.

Patients who detect any amount of ketones should always record the test results. The results should be discussed with a physician on the patient’s next scheduled diabetes appointment.