What is diabetic ketoacidosis? Diabetic ketoacidosis (DKA) is a life-threatening diabetes problem that happens when the body has too little insulin. Without enough insulin, the body breaks down fat too fast, and the liver turns it into acids called ketones. When ketones build up, the blood becomes acidic. DKA is a medical emergency that needs care right away.
Key takeaways
- DKA happens when insulin is too low. The body breaks down fat too fast, ketones build up, and the blood becomes acidic, according to MedlinePlus.
- The Centers for Disease Control and Prevention (CDC) says DKA is most common in type 1 diabetes, but people with type 2 diabetes can get it too. It is sometimes the first sign of diabetes.
- Early signs include strong thirst and urinating a lot more than usual. If DKA is not treated, the CDC says more severe signs, such as fast, deep breathing, fruity-smelling breath, and vomiting, can appear quickly.
- The CDC names illness and insulin problems, such as missed shots or a clogged insulin pump, as the two most common causes.
- The CDC says people with DKA are treated in the emergency room or admitted to the hospital. Call 911 for high ketones, trouble breathing, confusion, or vomiting that keeps you from keeping food or drinks down.
What Happens in the Body During DKA?
Insulin helps sugar (glucose) move from the blood into cells, where it is used for energy. The CDC explains that when the body does not have enough insulin, the liver breaks down fat for fuel instead. This process makes acids called ketones. When too many ketones are made too fast, they can build up to dangerous levels.
MedlinePlus adds that the liver normally makes some ketones when it has been a long time since your last meal, and the muscles and heart use them for fuel. In DKA, the signal from insulin is so low that fat breaks down faster than the body can handle. Ketones build up in the blood and make it acidic. At the same time, the liver makes a large amount of glucose, so blood sugar usually climbs too.
Doctors confirm DKA with blood and urine tests. The American Diabetes Association (ADA) lists these criteria in its 2026 Standards of Care, and all of them must be met. They are hospital tests, not numbers to check at home.
| What doctors measure | ADA 2026 criteria for DKA |
|---|---|
| Blood sugar | 200 mg/dL or higher, or a known history of diabetes |
| Ketones | Blood beta-hydroxybutyrate of 3.0 mmol/L or higher, or a urine ketone strip reading of 2+ or higher |
| Acid in the blood | pH below 7.3 and/or bicarbonate below 18 mmol/L |
The blood sugar line includes a known history of diabetes because DKA does not always come with very high blood sugar. ADA says about 10% of people with DKA have euglycemic DKA, with blood sugar below 200 mg/dL. Our guide to euglycemic DKA explains why it can be missed.
What Are the Warning Signs of DKA?
The CDC says DKA usually develops slowly. Early symptoms include:
- Being very thirsty
- Urinating a lot more than usual
If DKA is not treated, the CDC says more severe symptoms can appear quickly, such as:
- Fast, deep breathing
- Dry skin and mouth
- Flushed face
- Fruity-smelling breath
- Headache
- Muscle stiffness or aches
- Being very tired
- Nausea and vomiting
- Stomach pain
The ADA also lists confusion, and MedlinePlus lists decreased alertness. Not everyone has every sign, and the pattern can differ from person to person. ADA's 2026 Standards of Care say DKA develops over hours to days.
The CDC also says DKA is sometimes the first noticeable sign of diabetes in people who have not been diagnosed. So these signs matter even in someone who does not know they have diabetes. Our guide to symptoms of high blood sugar covers earlier signs, and why diabetes causes frequent urination explains one of the early symptoms.
What Causes DKA?
The CDC says very high blood sugar and low insulin levels lead to DKA. It names two causes as the most common:
- Illness. When you are sick, you may not be able to eat or drink as much as usual, which can make blood sugar hard to manage.
- Insulin problems. These include missed insulin shots, a clogged insulin pump, or the wrong insulin dose.
Other causes on the CDC's list include heart attack or stroke, physical injury such as from a car accident, alcohol or drug use, and certain medicines, such as some diuretics (water pills) and corticosteroids.
Infection. A 2024 consensus report on hyperglycemic crises from the ADA and four other diabetes organizations says infection is the most common trigger of DKA worldwide, found in 14% to 58% of cases. If infections keep coming back, see whether recurrent UTIs can be a sign of diabetes.
Medicines. ADA 2026 says some medicine classes can contribute to DKA, including glucocorticoids (steroids such as prednisone), antipsychotic medicines, immune checkpoint inhibitors used in cancer care, and SGLT2 inhibitors, a class of diabetes medicines. Never stop a prescribed medicine on your own. Ask your care team whether any of yours raise your risk. See what medications raise blood sugar and does prednisone raise blood sugar.
Cost. The consensus report says insulin rationing, which means skipping doses, using less insulin than prescribed, or delaying buying insulin to save money, has been reported in up to 20% of people treated with insulin in the United States. It links cost-related rationing to a higher risk of DKA. If cost is a problem, tell your care team or pharmacist.
Who Is at Risk for DKA?
The ADA says DKA can affect anyone with diabetes. The consensus report says most DKA events occur in adults ages 18 to 44 (61.7%) and in people with type 1 diabetes (70.6%).
ADA 2026 lists these risk factors for hyperglycemic crises, which include DKA:
- Type 1 diabetes or a severe lack of insulin
- Younger age
- A past hyperglycemic crisis or a past severe low blood sugar crisis
- Diabetes complications or other long-term health conditions
- Depression, bipolar disorder, eating disorders, or other behavioral health conditions
- Alcohol or substance use
- A high A1C
- Insulin rationing
- SGLT2 inhibitor use
- Social and economic barriers to care
The ADA's guide to managing ketones also lists pregnancy, being sick, stressed, or dehydrated, fasting or very low-carb eating, a past DKA episode, and being a young child, teen, or older adult.
People with type 2 diabetes are not immune. Our guide to whether type 2 diabetics can get DKA covers their risks, including a pattern called ketosis-prone type 2 diabetes. People with type 2 diabetes can also develop a related emergency called hyperosmolar hyperglycemic state (HHS), which MedlinePlus says involves extremely high blood sugar and few or no ketones.
Is DKA the Same as Ketosis From Fasting or a Low-Carb Diet?
No. Ketones alone do not mean DKA. MedlinePlus explains that the liver normally makes ketones when you have gone a long time without eating. In DKA, insulin is very low, ketones build up too quickly, and the blood becomes acidic.
Doctors also look for other causes of high ketones. The consensus report lists starvation ketosis, alcoholic ketoacidosis, and ketosis linked to pregnancy or to severe vomiting during pregnancy (hyperemesis) among the conditions to consider.
For people with diabetes, though, fasting and very low-carb eating are not risk-free. The ADA lists both among the risk factors for ketones. The consensus report also lists very low-carb diets and prolonged fasting as DKA risk factors for people with type 2 diabetes who take SGLT2 inhibitors. Talk with your care team before fasting or starting a very low-carb diet. Our guides to ketones in urine and whether intermittent fasting is safe for diabetics explain more.
How Is DKA Treated?
The CDC says people with DKA are treated in the emergency room or admitted to the hospital. Treatment will likely include:
- Fluids, to replace what was lost through frequent urination and to help dilute extra sugar in the blood
- Electrolytes, minerals in the body that too little insulin can lower
- Insulin, which the CDC says reverses the conditions that cause DKA
- Medicines for the cause, such as antibiotics for an infection
MedlinePlus says most people respond to treatment within 24 hours, though recovery sometimes takes longer. Without treatment, DKA can lead to severe illness or death. Possible complications include fluid buildup in the brain (cerebral edema), cardiac arrest, and kidney failure.
With treatment, the consensus report says deaths from DKA have fallen below 1%. ADA 2026 reports recent hospital death rates ranging from 0.2% in type 1 diabetes to 1.0% in type 2 diabetes.
DKA can also come back. The consensus report says 10% to 20% of people are readmitted to the hospital after DKA or another hyperglycemic crisis, mostly within 2 weeks of going home. ADA 2026 advises a follow-up visit within 1 month of leaving the hospital, or within 1 to 2 weeks if diabetes medicines were changed. If you do not have a regular diabetes clinician, our guide to finding a diabetes doctor near you explains where to start.
How Can You Lower Your Risk of DKA?
The CDC says you can take steps to help prevent DKA:
- Check your blood sugar often, especially if you are sick.
- Keep your blood sugar in your target range as much as possible.
- Take medicines as prescribed, even if you feel fine.
- Talk to your doctor about how to adjust your insulin based on what you eat, how active you are, or if you are sick.
The ADA adds:
- Make a sick-day and ketone plan with your care team that covers when to check ketones and when to call.
- Keep ketone strips or a blood ketone meter at home, and make sure the strips have not expired. The ADA prefers a blood ketone meter.
- Keep taking insulin as directed. The ADA says never to stop unless your doctor tells you to.
- Drink water or sugar-free fluids to stay hydrated.
When to check ketones. The CDC advises checking your blood sugar every 4 to 6 hours and checking your urine for ketones if you are sick or your blood sugar is 250 mg/dL or higher. It also says to test for ketones if you have any DKA symptoms. The ADA suggests checking when blood sugar has been 250 mg/dL or higher for 2 hours or more, and notes that your care team may choose a lower level, such as 200 mg/dL. Ketone kits are sold over the counter.
Blood or urine? ADA 2026 cites a 6-month randomized trial in which checking blood ketones instead of urine ketones cut hospital or emergency room care by about half. The consensus report adds that urine tests can underestimate ketone levels early in DKA. Ask your care team which test fits you. Our diabetes sick day rules guide covers what to ask.
Education and monitoring. ADA 2026 says structured diabetes self-management education that includes problem-solving is effective at reducing DKA admissions. See diabetes self-management education and support to learn what it covers. The consensus report also describes a nationwide study in France in which access to a continuous glucose monitor (CGM) was linked to a later drop in DKA hospital stays of 53% in type 1 diabetes and 47% in type 2 diabetes.
A simple record of readings, symptoms, and sick days can make follow-up visits easier. Our blood sugar journal prompts can help you start one.
When Should You Get Help?
Emergency: Call 911 or go to the emergency room for high ketones, trouble breathing, fruity-smelling breath, confusion or decreased alertness, or vomiting that keeps you from keeping food or drinks down. The CDC also advises emergency care if your blood sugar stays at 300 mg/dL or higher or you have several signs of DKA. The ADA says blood ketones of 1.6 mmol/L or higher need emergency care.
Same day: Contact your care team right away if a home test shows ketones, as MedlinePlus advises. Also call if you are sick and your blood sugar stays above your target, or if you are not sure how to follow your sick-day plan.
Prompt appointment: After any DKA hospital stay, book a follow-up visit within 1 month, or within 1 to 2 weeks if your medicines changed, as ADA 2026 advises. Also book a visit to make or update a sick-day plan, or if you have trouble paying for insulin or supplies.
Frequently Asked Questions
What is the main cause of DKA?
DKA is caused by too little insulin. The CDC says the two most common causes are illness and insulin problems, such as missed shots, a clogged insulin pump, or the wrong dose. Heart attack, stroke, injury, alcohol or drug use, and some medicines can also lead to DKA.
Can people with type 2 diabetes get DKA?
Yes. The CDC says DKA is most common in type 1 diabetes, but people with type 2 diabetes can develop it too. MedlinePlus says people with type 2 diabetes can develop euglycemic DKA, usually triggered by long periods of high blood sugar, missed medicine doses, a side effect of some medicines, or a severe illness or infection.
How fast does DKA develop?
ADA 2026 says DKA develops over hours to days. The CDC says it usually develops slowly at first, but more severe symptoms can appear quickly if it is not treated. Do not wait to see whether symptoms pass.
What does DKA breath smell like?
The CDC describes it as fruity-smelling breath. Fruity breath is also on the CDC list of reasons to go to the emergency room or call 911, so do not wait for other symptoms to appear.
Can you have DKA with normal blood sugar?
Yes. This is called euglycemic DKA. ADA 2026 says about 10% of people with DKA have blood sugar below 200 mg/dL. It is linked to SGLT2 inhibitors, eating much less than usual, pregnancy, alcohol use, and liver failure.
Can DKA be prevented?
The CDC says you can take steps to help prevent it. Check your blood sugar often, especially when sick, take medicines as prescribed even if you feel fine, and talk with your doctor about adjusting insulin. The ADA also recommends a sick-day and ketone plan made with your care team.
References
- Centers for Disease Control and Prevention. “Diabetic Ketoacidosis.” Accessed October 2026.
- American Diabetes Association. “DKA: Signs, Symptoms, and Treatment.” Accessed October 2026.
- American Diabetes Association. “Managing Ketones with Diabetes.” Accessed October 2026.
- MedlinePlus. “Diabetic Ketoacidosis.” Accessed October 2026.
- MedlinePlus. “Diabetic Hyperglycemic Hyperosmolar Syndrome.” Accessed October 2026.
- American Diabetes Association Professional Practice Committee for Diabetes. “16. Diabetes Care in the Hospital: Standards of Care in Diabetes—2026.” Diabetes Care. 2026;49(Suppl. 1):S339–S355. Accessed October 2026.
- American Diabetes Association Professional Practice Committee for Diabetes. “6. Glycemic Goals, Hypoglycemia, and Hyperglycemic Crises: Standards of Care in Diabetes—2026.” Diabetes Care. 2026;49(Suppl. 1):S132–S149. Accessed October 2026.
- Umpierrez GE, Davis GM, ElSayed NA, et al. “Hyperglycemic Crises in Adults With Diabetes: A Consensus Report.” Diabetes Care. 2024;47(8):1257–1275. Accessed October 2026.
- Johnson SK. “Adolf Kussmaul: Distinguished Clinician and Medical Pioneer.” Clinical Medicine & Research. 2009;7(3):107–112. Historical context only. Accessed October 2026.
Next Steps
Ask your care team for a written sick-day plan that says when to check ketones, which test to use, what to drink, what to do about your medicines, and when to call 911. Keep the plan and your ketone supplies where you and your family can find them quickly.
For adults with type 2 diabetes or prediabetes who want lifestyle education alongside clinical care, the Done With Diabetes™ program offers a type 2 diabetes protocol that organizes learning about meals, movement, sleep, and stress. It does not diagnose or treat DKA or diabetes, interpret ketone or glucose results, change medicines, or replace emergency or clinical care.