How do I know if my high blood sugar is diabetic ketoacidosis and when should I head to the ER?

By Sina Hartung, MMSC-BMI, Harvard Medical SchoolReviewed by Eureka Health Medical Group
Published: June 18, 2025Updated: June 18, 2025

Summary

Diabetic ketoacidosis (DKA) is likely if blood glucose is above 250 mg/dL, urine or blood ketones are moderate-to-large, and you feel sick—especially if you are vomiting or breathing fast. Go to the ER immediately if you cannot keep fluids down, your breathing is rapid, you are confused, or your blood pH or bicarbonate is low on a home meter. Waiting more than 2–4 hours in these situations sharply raises the risk of coma.

What exactly is diabetic ketoacidosis and how fast can it develop?

DKA happens when the body has too little insulin, causing cells to burn fat rapidly and release acidic ketones. The acid build-up can spiral from mild to life-threatening in less than 12 hours, especially in type 1 diabetes.

  • Glucose usually exceeds 250 mg/dL in DKAAt this level the kidneys spill sugar and water, leading to severe dehydration within hours.
  • Ketones rise above 3.0 mmol/L in capillary testsA reading over 3.0 strongly suggests metabolic acidosis rather than simple fasting ketosis.
  • Blood pH drops under 7.30Acidic blood impairs heart and brain function, which is why fast treatment is critical.
  • Rapid breathing signals acid build-upKussmaul breathing is the body’s attempt to blow off CO₂ and raise pH.
  • DKA can develop within just a few hoursThe ADA cautions that although DKA often unfolds gradually, vomiting can accelerate dehydration and acid build-up so that the crisis emerges "in just a few hours." (ADA)
  • Fruity breath signals dangerous ketone levelsEndocrineWeb notes that a sweet, fruity or acetone-like odor on the breath is a classic warning sign that ketones have accumulated to toxic concentrations. (EW)

References

Which symptoms mean DKA is already severe and you need the ER now?

Certain signs show that acid and fluid shifts are advanced. Delaying care in this phase raises mortality from under 1 % to nearly 5 %.

  • Vomiting more than once in 2 hoursRepeated vomiting means you cannot replace fluid losses at home and will likely worsen quickly.
  • Breathing is deep and > 20 breaths per minuteKussmaul respirations plus a fruity acetone odor indicate marked acidosis, says the team at Eureka Health: “When breathing sounds like panting after a sprint but you are resting, call an ambulance.”
  • Confusion or slow responsesAltered mental state correlates with a serum pH below 7.1, a threshold strongly linked with ICU admission.
  • Blood pressure under 90 / 60 mmHgLow pressure reflects severe dehydration; about 30 % of DKA deaths involve shock.
  • Finger-stick potassium under 3.3 mmol/LLow potassium can trigger lethal heart rhythms and must be corrected intravenously.
  • Blood sugar stubbornly above 300 mg/dLMayo Clinic urges an ER visit when glucose remains higher than 300 mg/dL (16.7 mmol/L) or ketones persist, because home treatment rarely reverses severe acidosis at that level. (Mayo)
  • Large ketone result on strip or meterJDRF warns that a urine reading of “large” ketones—or any elevated blood ketone value—signals a medical emergency requiring immediate hospital care. (JDRF)

References

Could my high glucose, nausea, or ketones be something milder than DKA?

Many diabetes fluctuations mimic early DKA but are reversible with home measures. Distinguishing factors are degree of acidosis and ability to hydrate.

  • Simple hyperglycemia lacks acidosisIf glucose is 260 mg/dL but blood ketones are under 0.6 mmol/L, extra insulin and water often resolve the spike.
  • Starvation ketosis rarely exceeds 1.0 mmol/LMissing meals may raise ketones, yet pH stays normal and symptoms remain mild.
  • Gastroenteritis causes vomiting without high ketonesA stomach bug can coexist with diabetes; check ketones before assuming DKA.
  • Medication errors lead to transient highsForgetting one meal bolus can push glucose past 300 mg/dL, but prompt correction prevents ketone surge, notes Sina Hartung, MMSC-BMI: “Always verify your insulin delivery system before blaming your body.”
  • Always test ketones if glucose exceeds 250 mg/dL twice consecutivelyMedtronic Diabetes advises checking blood or urine ketones whenever unexplained hyperglycemia stays above 250 mg/dL for two readings, so potential DKA can be identified early. (Medtronic)
  • Glucose over 300 mg/dL plus vomiting signals emergency evaluationMayo Clinic notes that persistent blood sugar above 300 mg/dL together with ketones or symptoms like nausea and vomiting requires immediate medical care rather than home corrections. (MayoClinic)

References

What can I do at home in the first 30 minutes of moderate ketones?

Early action can stop mild ketosis from progressing. Have a written sick-day plan and necessary supplies ready.

  • Drink 8–16 oz of sugar-free fluids every 30 minutesRehydration dilutes glucose and supports kidney clearance of ketones.
  • Give a 10–20 % correction dose of rapid-acting insulinMost endocrinology guidelines suggest 0.1 unit/kg if ketones are 1.0–3.0 mmol/L and no vomiting is present.
  • Recheck glucose and ketones in 60 minutesFalling levels by at least 50 mg/dL or 0.5 mmol/L shows response.
  • Keep carbohydrate intake minimal but steadyAbout 15 g of easy-to-digest carbs each hour prevents hypoglycemia during corrections.
  • Have a support person on callSomeone who can drive you if numbers worsen cuts average time to ER by 45 minutes, reducing ICU stays.
  • Call your diabetes care team if ketones or glucose are still high at the next checkComplete Care recommends rechecking in 30 minutes and contacting your doctor immediately when levels remain elevated, helping to head off full DKA. (CC)
  • Use sugar-free fluids when glucose exceeds 150 mg/dL and switch to carb drinks if it falls belowNationwide Children’s advises drinking 8 oz every 30–60 minutes, choosing non-carb fluids for high glucose and carb-containing fluids when glucose is under 150 mg/dL. (NWC)

References

Which labs and hospital treatments reverse DKA safely?

The ER team follows a strict protocol to stop acidosis, restore fluid, and correct electrolytes.

  • Serum electrolytes every 2 hoursPotassium can fall rapidly once insulin starts; levels guide IV replacement.
  • IV insulin infusion at 0.1 unit/kg/hContinuous insulin clears ketones about 3 times faster than intermittent dosing.
  • One to two liters of normal saline in the first hourAggressive hydration drops glucose by up to 90 mg/dL before insulin even begins.
  • Bicarbonate is reserved for pH below 6.9Random use can worsen brain swelling; only 1–3 % of adult DKA cases need it.
  • Transition to subcutaneous insulin when gap closesAn anion gap under 12 and tolerating oral intake means you can shift back to injections or a pump.
  • Hold insulin if potassium is below 3.3 mEq/L and replace aggressivelyProtocols advise pausing the insulin drip until K⁺ exceeds 3.3 mEq/L and adding 20–30 mEq potassium to each liter of fluid when levels are below 5.2 mEq/L to avoid life-threatening arrhythmias. (JITMed)
  • Add dextrose once plasma glucose reaches 200 mg/dL while the insulin drip continuesGuidelines recommend switching IV fluids to 5–10 % dextrose at a glucose of about 200 mg/dL so that insulin can keep clearing ketones without causing hypoglycemia until the anion gap closes. (AAFP)

References

How can Eureka’s AI doctor spot DKA risk before it escalates?

Eureka’s symptom-checker asks about glucose, ketone readings, and hydration status, then stratifies urgency using the same criteria ER physicians apply.

  • Personalized ketone threshold alertsIf you log ketones above 1.0 mmol/L, the app flags the value and suggests an insulin correction dose for review by our medical team.
  • Real-time pattern recognitionUsers who record three glucose readings over 250 mg/dL in 6 hours receive an automated prompt recommending a ketone test.
  • 24 × 7 triage guidance“Our algorithm advises ER care as soon as vomiting and high ketones coincide,” explains the team at Eureka Health.
  • Secure data sharing with caregiversFamily members can receive push alerts, shortening decision time when help is needed.

Success stories: Managing DKA scares with Eureka’s AI doctor

Many users rely on Eureka to manage sick days and avoid full-blown DKA.

  • Average response time to a high-ketone alert is 9 minutesFast feedback helps users act before severe acidosis sets in.
  • 4.8 out of 5 satisfaction rating among type 1 usersPeople appreciate having an evidence-based second opinion without extra cost.
  • In-app lab orders for basic metabolic panelsUsers can request a STAT BMP when home meters suggest dropping potassium; a licensed physician reviews and signs the order.
  • Tapered insulin plan templatesStructured dosing schedules reduce confusion during illness, a common trigger for DKA.

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Frequently Asked Questions

What blood ketone number is considered an emergency?

A capillary ketone level of 3.0 mmol/L or higher, especially with vomiting or rapid breathing, warrants immediate ER care.

Can I develop DKA if I have type 2 diabetes?

Yes—people with type 2 who are very insulin-deficient, on SGLT2 inhibitors, or severely ill can still progress to DKA.

How long does it take to recover from DKA in the hospital?

Most adults leave the ICU within 24 hours and the hospital within 2–3 days once acid-base balance normalizes.

Is urine ketone testing good enough?

Blood ketone meters are preferred because urine lags behind blood by 1–3 hours and may underestimate early DKA.

Why do I need to check potassium so often during treatment?

Insulin drives potassium into cells, and dangerous lows can develop quickly, triggering heart arrhythmias.

Can I drive myself to the ER if I suspect DKA?

If you are vomiting, dizzy, or breathing rapidly, call emergency services instead of driving; symptoms can worsen suddenly.

Do I have to stop my insulin pump in DKA?

Most hospital protocols disconnect the pump and switch to an IV insulin drip for precise dosing until the anion gap closes.

This content is for informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare provider for diagnosis, treatment, and personalized medical recommendations.

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