Your body runs on glucose. It’s the fuel that keeps your brain working and your muscles moving. But without enough insulin to ferry the glucose into your cells, the body breaks down fat for fuel instead of glucose, causing ketones to form and circulate in the bloodstream. If large quantities of ketones accumulate, blood acidity rises, and you have what’s known as diabetic ketoacidosis, or DKA for short, an urgent medical problem.
High blood glucose, usually present in DKA, causes frequent urination and dehydration, which raises blood glucose further. Untreated, DKA can cause coma and even death.
People with type 1 diabetes are most at risk because they no longer produce insulin and are completely dependent on injected or pumped insulin to keep blood glucose and ketones in check. In fact, many people are diagnosed with type 1 following an episode of DKA. People with type 2 diabetes don’t make enough insulin to maintain normal blood glucose levels, but the insulin they do produce is usually enough to suppress ketone formation. They may develop DKA amid extreme bodily stress, such as a serious infection.
Stress hormones during illness can cause insulin, injected or produced by the body, to work less effectively, bringing on higher ketone levels, says Nicole Glaser, MD, professor of pediatrics at the University of California Davis School of Medicine. Missing insulin doses or using expired insulin, which is less effective, can also spur the production of ketones.
Another problem that can increase the risk for DKA is a pump malfunction. If your cannula or needle kinks or has a blockage (what’s known in pump speak as an occlusion), insulin may not get into your body—and you may not become aware of this until it’s too late. Ketone production and the processes of DKA will generally begin developing by about four to six hours in that situation, Glaser says, resulting in DKA within a day if untreated.
If your meter or continuous glucose monitor (CGM) persistently reads 250 mg/dl or greater despite attempts to lower glucose with extra insulin, check for ketones, says Adrian Vella, MD, professor of medicine in the Division of Endocrinology at the Mayo Clinic in Rochester, Minnesota. Other reasons to test for ketones: You’re sick with an infection or other illness, or you have symptoms of ketoacidosis (see “Ketones Rising,” below), regardless of blood glucose level, says Glaser.
While rare, it is possible to develop DKA without high blood glucose—what’s known as euglycemic diabetic ketoacidosis (eDKA). The main cause of eDKA is an illness that involves vomiting and very little food intake for prolonged periods of time, Glaser says. Drugs in the SGLT-2 inhibitor class can also increase the risk of eDKA. In both cases, glucose levels may be in the 100 to 200 mg/dl range, rather than the 500 mg/dl or higher typical of DKA. SGLT-2 inhibitors lower blood glucose by causing you to excrete excess glucose through the urine. Because doctors expect blood glucose to be higher with DKA, this can lead to a missed DKA diagnosis. The FDA recently issued a warning regarding this potential side effect of SGLT-2 inhibitors. Because the problem is more common with type 1 diabetes, these drugs shouldn’t be used by people with type 1. Euglycemic DKA can sometimes occur in people with type 2.
A simple at-home test for blood or urine ketones will let you know if large quantities of ketones are present. Both types of strips will give you an accurate reading, but blood tests reflect ketone levels in real time. Levels in the urine reflect what happened in the past several hours, as urine was accumulating in the bladder.
Here’s what to look for when you test:
Blood Ketones—A blood ketone meter is designed to check for ketones using a test strip and finger-stick blood sample. At this time, the Nova Max Plus meter is available in the United States. A level of 1 mmol or higher warrants a call to your doctor to work out a treatment plan, which may include drinking water in a prescribed amount and taking extra rapid-acting or regular insulin. If your levels are above 3 mmol, particularly if your blood glucose is above 300 mg/dl, go to the hospital emergency room, says Guillermo Umpierrez, MD, CDE, professor of medicine in the Division of Endocrinology and Metabolism at Emory University School of Medicine.
Urine Ketones—A dipstick passed through a stream of urine changes colors based on a number of ketones present. You’ll compare the dipstick to a card or label (included with the strips) with corresponding colors that indicate negative (none), trace, small, moderate, and large amounts of ketones. Glaser recommends calling your doctor if your test reads “small” or higher, just to be safe.
If you feel under the weather, test for ketones twice a day and continue to check twice a day as long as you feel sick—whether or not you have positive ketone test results. “The main reason people get into trouble with DKA is that many of the symptoms seem like a stomach virus, and they forget to test their ketones,” Glaser says.
It’s important to stay in communication with your health care team throughout your bout with ketones. According to the American Diabetes Association’s 2017 Standards of Medical Care in Diabetes, high blood glucose accompanied by elevated ketone levels, vomiting, or a change in mental status requires an immediate adjustment to your treatment regimen, and your care team can help you with that. Treatment generally involves at-home ketone testing, drinking larger amounts of water to flush out ketones, replacing electrolytes, and using “judicious” amounts of insulin to lower blood glucose and stop ketone production, says Vella. “We’ll have [our patients] call every few hours with an update on how they’re feeling, what their ketone level is, what their blood sugar level is, and [we] revise what we’re doing from there,” says Glaser. With early treatment, you can avoid a trip to the emergency room for insulin, ketone monitoring, and intravenous fluids.
Diabetic ketoacidosis (DKA) can develop quickly—within several hours in some cases, says Nicole Glaser, MD, professor of pediatrics at the University of California Davis School of Medicine. If treated early at an emergency department with IV insulin and fluids, most people recover without any issues. But if treatment begins in the later stages of DKA, admission to the hospital intensive care unit may be required.
- Dry mouth and excessive thirst
- Frequent urination
- High blood glucose
- High levels of ketones
- Feeling of tiredness
- Nausea, vomiting, or abdominal pain
- Difficulty breathing
- Fruity odor on breath
- Mental confusion