Diabetic ketoacidosis (DKA) typically announces itself with intense thirst, frequent urination, and nausea, and it can escalate from early discomfort to a life-threatening emergency within 24 hours. Recognizing the warning signs early is critical because DKA is one of the most dangerous complications of diabetes, particularly type 1.
What Happens in Your Body During DKA
DKA starts when your body doesn’t have enough insulin to move sugar from your blood into your cells for energy. Without that fuel source, your body switches to breaking down stored fat. That fat breakdown floods your liver with fatty acids, which get converted into chemicals called ketones. In small amounts, ketones are harmless. But when insulin is severely lacking, ketone production spirals out of control, and these acidic compounds build up in your blood faster than your body can clear them. The result is a dangerous drop in blood pH that affects virtually every organ system.
This cascade is driven by a specific hormonal imbalance: insulin drops while glucagon (a hormone that raises blood sugar) surges. That combination activates enzymes that pull fat out of storage and funnel it into ketone production. Meanwhile, your blood sugar keeps climbing because without insulin, glucose has nowhere to go.
The Earliest Signs
The first symptoms of DKA overlap with general high blood sugar, which is why they’re easy to dismiss. Extreme thirst that doesn’t go away no matter how much you drink is one of the most common early signals. You’ll also notice you’re urinating far more than usual. This happens because excess glucose in your blood spills into your urine and pulls water along with it, rapidly dehydrating you.
Other early signs include unusual fatigue, blurred vision, and unexplained weight loss. If you check your blood sugar during this phase, it will typically read 250 mg/dL or higher. For some people, especially children, these symptoms are the very first indication they have diabetes at all.
Signs That DKA Is Progressing
As ketone levels rise and your blood becomes more acidic, the symptoms shift from uncomfortable to alarming. Nausea, vomiting, and abdominal pain are hallmarks of this stage. The stomach pain can be severe enough to mimic appendicitis or a stomach virus, which sometimes leads to misdiagnosis, particularly in children experiencing their first DKA episode.
Two distinctive signs set DKA apart from ordinary illness:
- Fruity-smelling breath. As your body tries to expel excess ketones, acetone (the same chemical in nail polish remover) exits through your lungs. The result is a noticeable sweet or fruity odor on your breath.
- Deep, rapid breathing. Your body compensates for the acid buildup by breathing faster and deeper than normal, trying to blow off carbon dioxide and restore blood pH. This pattern, sometimes called Kussmaul breathing, looks and sounds different from the panting of exertion. It’s steady, labored, and unusually deep.
Confusion, difficulty concentrating, and drowsiness signal that the acidosis is becoming severe. If left untreated, this progresses to loss of consciousness and coma.
How Fast It Develops
DKA can go from first symptoms to emergency in under 24 hours. The speed depends on the trigger. A missed insulin dose or an insulin pump malfunction can cause a rapid spiral in just a few hours, while DKA triggered by an illness or infection may build more gradually over a day or two. Either way, this is not a condition that gives you days to wait and see. Once vomiting starts, dehydration accelerates and the situation can deteriorate quickly.
Warning Signs in Children
Children under five are at the highest risk for DKA as a first presentation of type 1 diabetes, and kids under two face an even greater risk. Because young children can’t always describe what they’re feeling, the signs look different. Parents may notice increased diaper wetness or sudden bedwetting in a previously toilet-trained child. Unusual irritability, lethargy, poor school performance, and lack of concentration are behavioral clues.
Children with DKA often appear thin and visibly dehydrated. Nausea, vomiting, and belly pain are common, and these symptoms frequently get mistaken for a stomach bug. If a child with these symptoms also seems unusually thirsty, is losing weight, or is breathing in a deep, rhythmic pattern, DKA should be considered immediately.
A rare but serious complication in children is brain swelling, which can develop during or after treatment. Warning signs include a new or worsening headache, repeated vomiting, sudden confusion, loss of bladder control, and changes in heart rate or breathing pattern.
When Blood Sugar Isn’t High
One of the most dangerous misconceptions about DKA is that it always comes with very high blood sugar. A form called euglycemic DKA can occur with blood sugar levels below 250 mg/dL, sometimes even in the near-normal range. This is most commonly seen in people taking a class of type 2 diabetes medications (SGLT2 inhibitors) that lower blood sugar by flushing glucose out through urine.
Because the blood sugar reading looks reassuring, euglycemic DKA is often caught late. In a review of 72 cases linked to SGLT2 inhibitors, the most common symptoms were nausea (48%), abdominal pain (38%), and vomiting (36%). Rapid breathing appeared in about a third of cases, and 10% had altered consciousness by the time they were diagnosed. If you take an SGLT2 inhibitor and develop persistent nausea, stomach pain, or rapid breathing, testing for ketones is essential even if your glucose looks fine.
How to Check at Home
Two home tests can catch DKA before it becomes an emergency: blood sugar checks and ketone tests. If your blood sugar is 250 mg/dL or above, or if you’re sick and have diabetes, check your blood sugar every four to six hours and test your urine for ketones.
Urine ketone strips give results in ranges:
- Small: less than 20 mg/dL
- Moderate: 30 to 40 mg/dL
- Large: above 80 mg/dL
A moderate or large result, combined with high blood sugar and symptoms like nausea or rapid breathing, means you need emergency care. Blood ketone meters are also available and give a more precise number. A reading of 3 mmol/L or higher on a blood ketone meter, along with symptoms, indicates DKA is likely already underway. If your blood sugar stays at or above 300 mg/dL, that alone warrants calling 911 or going to the emergency room.
Common Triggers to Watch For
DKA rarely strikes out of nowhere. The most frequent triggers are situations where insulin levels drop or the body’s demand for insulin spikes. Missed insulin doses and insulin pump failures are leading causes. Illness and infection are another major trigger because your body releases stress hormones that raise blood sugar and increase insulin resistance. Even a common cold or urinary tract infection can tip the balance.
Other triggers include surgery, physical trauma, heavy alcohol use, certain medications (including steroids and the SGLT2 inhibitors mentioned above), and, in some cases, emotional stress. For people with type 1 diabetes who are newly diagnosed or don’t yet know they have the condition, DKA may be the event that brings them to the hospital for the first time.