Diabetic ketoacidosis (DKA) is a serious, potentially life-threatening complication of diabetes that occurs when your body doesn’t have enough insulin to move sugar into cells for energy. Without insulin, your body breaks down fat at a dangerously fast rate, producing acidic byproducts called ketones that build up in your blood and make it acidic. DKA most commonly affects people with type 1 diabetes but can also occur in type 2 diabetes under certain conditions.
How DKA Develops in the Body
The chain reaction behind DKA starts with a shortage of insulin. Insulin is the hormone that lets your cells absorb glucose from the bloodstream. When insulin drops too low, either because the body stops making it or because someone misses doses, cells are effectively starving even though blood sugar is high. Your body responds by switching to an emergency fuel source: fat.
At the same time, stress hormones like glucagon, cortisol, and adrenaline surge. These hormones tell the liver to dump even more glucose into the blood and break down proteins for additional fuel. The result is blood sugar climbing higher and higher while fat is being broken down rapidly. That fat breakdown produces ketone bodies, which are mildly acidic. In small amounts, ketones are harmless. In the large quantities generated during DKA, they overwhelm the blood’s ability to stay at a normal pH, tipping it toward dangerous acidity. That acid buildup is what makes DKA a medical emergency rather than just high blood sugar.
Common Triggers
The single biggest trigger for DKA is missed or skipped insulin doses. In one study of adults with type 1 diabetes, insulin non-adherence accounted for 51.2% of DKA cases. Sometimes this is intentional (skipping doses due to cost, mental health struggles, or disordered eating), and sometimes it’s accidental, like a pump malfunction. Among insulin pump users specifically, 55% of DKA episodes were linked to a defect in the pump or tubing.
Infection is the other major trigger, present in roughly 25% of cases. Illnesses like urinary tract infections, pneumonia, or even the flu increase stress hormones that work against insulin, creating the imbalance that sets DKA in motion. Other triggers include heart attacks, strokes, certain medications (particularly steroids), heavy alcohol use, and sometimes no identifiable cause at all. DKA can also be the first sign of diabetes in someone who hasn’t been diagnosed yet, particularly children and young adults with new-onset type 1 diabetes.
Symptoms to Recognize
DKA usually builds over hours to a day or two, and the early symptoms are easy to dismiss. You’ll notice extreme thirst and frequent urination as your kidneys try to flush out the excess sugar. These are the same symptoms as general high blood sugar, so many people don’t realize something more dangerous is developing.
As ketone levels rise, more severe symptoms appear quickly:
- Fast, deep breathing: Your body’s attempt to blow off excess acid through the lungs. This distinctive pattern of rapid, labored breathing is one of the hallmark signs.
- Fruity-smelling breath: Caused by acetone, one of the ketone bodies, being exhaled.
- Nausea, vomiting, and stomach pain: These gastrointestinal symptoms are common enough that DKA is sometimes mistaken for a stomach bug or even appendicitis, especially in children.
- Extreme fatigue and confusion: As the blood becomes more acidic, brain function is affected.
- Dry skin and mouth, flushed face, headache, and muscle aches round out the picture.
If left untreated, DKA progresses to loss of consciousness and coma. The window between “feeling off” and “medical emergency” can be surprisingly short, particularly if vomiting prevents you from keeping down fluids or oral medications.
How DKA Is Diagnosed
In the emergency department, DKA is confirmed through blood tests. The key markers are high blood sugar, high ketone levels, and acidic blood. The preferred ketone measurement is a specific type called beta-hydroxybutyrate, which is more accurate than the older urine ketone strips. A beta-hydroxybutyrate level of 3.0 mmol/L or higher confirms significant ketosis. Urine strips can underestimate how many ketones are actually present when you first arrive and overestimate them as you’re getting better, making them less reliable for tracking the course of treatment.
DKA is also classified by severity (mild, moderate, or severe) based on how acidic the blood has become and how alert the person is. This classification guides how aggressively the medical team treats it.
What Treatment Looks Like
DKA requires hospital treatment, often in an intensive care unit for moderate or severe cases. The treatment addresses three problems simultaneously: dehydration, insulin deficiency, and electrolyte imbalances.
Most people with DKA are significantly dehydrated because high blood sugar pulls fluid out of cells and drives excessive urination. Intravenous fluids are the first priority, often starting before anything else. Insulin is given through an IV drip to slowly bring blood sugar down and, more importantly, to shut off the ketone production that’s making the blood acidic. The key word is “slowly.” Dropping blood sugar too fast can cause dangerous fluid shifts, so the rate is carefully controlled.
The trickiest part of DKA treatment is managing potassium. Insulin pushes potassium from the bloodstream into cells, which can cause potassium levels to plummet. Low potassium is dangerous in its own right, potentially causing heart rhythm problems and even respiratory failure. For this reason, doctors check potassium before starting insulin. If levels are already low (below 3.5 mEq/L, which happens in 5% to 10% of patients on arrival), insulin is delayed until potassium is brought up to a safe range. Throughout treatment, potassium is monitored frequently and replaced as needed.
How Long Recovery Takes
DKA is considered resolved when ketone levels drop below 0.6 mmol/L and the blood’s pH returns to 7.3 or above, or bicarbonate (the body’s acid buffer) rises to 18 mmol/L or higher. For most people, this takes somewhere between 12 and 36 hours of continuous IV treatment, depending on severity.
Once the crisis is resolved, you’ll transition from IV insulin back to injections or your insulin pump. This transition is carefully timed so there’s no gap in insulin coverage that could restart ketone production. A hospital stay of two to three days is typical for uncomplicated DKA, though severe cases may take longer. After discharge, you’ll likely feel wiped out for several days as your body recovers from the metabolic stress.
Risks and Complications
The most feared complication of DKA treatment is brain swelling (cerebral edema), which occurs far more often in children than adults. Clinically significant brain swelling happens in 0.3% to 0.9% of pediatric DKA episodes. Children with more severe acidosis at the time of diagnosis are at the highest risk, and symptoms typically appear within the first 12 hours of treatment. Subclinical brain swelling, detectable on imaging but not causing obvious symptoms, is actually quite common in children during DKA treatment. One study found that 56% of children showed signs of brain swelling on scans, even when they appeared neurologically normal.
Other complications include dangerously low potassium (as described above), low blood sugar from too-aggressive insulin treatment, fluid overload, and, in rare cases, blood clots. The mortality rate for DKA has dropped significantly with modern treatment but remains around 1% to 5% in adults, with higher rates in older patients and those with severe underlying illnesses.
Preventing Future Episodes
If you have type 1 diabetes, the most effective prevention is consistent insulin use and having a sick-day plan. Illness increases your insulin needs, so the instinct to eat less and take less insulin during a stomach bug is exactly backwards. You typically need more insulin when sick, not less, and should check blood sugar and ketones more frequently.
Home ketone meters that measure beta-hydroxybutyrate from a finger stick are more reliable than urine strips and give you an earlier warning. Testing for ketones any time your blood sugar is above 250 mg/dL, or when you’re ill, lets you catch rising levels before they become an emergency. If ketones are elevated and you can’t bring them down with extra insulin and fluids within a few hours, that’s the point to get to an emergency department rather than waiting for symptoms to worsen.
For insulin pump users, checking infusion sites regularly and having backup injection supplies on hand protects against the pump malfunctions that account for more than half of DKA episodes in that group. Because insulin pumps use only fast-acting insulin with no long-acting background dose, a pump failure can lead to DKA within just a few hours.