Ketoacidosis is a dangerous condition where your blood becomes too acidic because your body produces extremely high levels of chemicals called ketones. It happens when your cells can’t get enough glucose for energy and instead break down fat at an overwhelming rate. The most common form, diabetic ketoacidosis (DKA), is a medical emergency that requires hospital treatment, but with proper care, the mortality rate is under 1%.
How Ketoacidosis Develops
Your body normally runs on glucose, a sugar that enters your cells with the help of insulin. When insulin is missing or not working properly, glucose builds up in your blood but can’t reach your cells. Your body responds by breaking down stored fat for fuel instead. That fat breakdown produces ketones, which are acidic byproducts.
In small amounts, ketones are harmless. People on low-carb diets or during fasting produce ketones at levels around 4 to 6 mmol/L in the blood. In ketoacidosis, that number climbs to 20 to 25 mmol/L, roughly four to five times higher. At those concentrations, ketones overwhelm your blood’s ability to stay at a safe pH, and your blood turns dangerously acidic. That acid shift disrupts how your organs function, particularly your brain, heart, and kidneys.
Ketoacidosis vs. Ketosis
These two terms sound similar but describe very different states. Ketosis is a normal metabolic process where your body burns fat and produces moderate ketone levels. It happens during fasting, prolonged exercise, or a ketogenic diet. Your blood stays at a safe pH, and the ketone levels remain well below dangerous thresholds.
Ketoacidosis is a pathological state. The key difference is both the volume of ketones produced and whether your body can regulate the process. In ketosis, insulin (even small amounts) acts as a brake on fat breakdown. In ketoacidosis, that brake is gone. Fat breaks down unchecked, ketones flood the bloodstream, and blood pH drops below 7.3 (normal is around 7.4). Even a small shift in blood pH can cause serious problems.
Types of Ketoacidosis
Diabetic Ketoacidosis (DKA)
This is the most common and well-known form. It occurs primarily in people with type 1 diabetes, where the body makes little or no insulin, but it also happens in type 2 diabetes. Blood sugar typically runs very high, between 200 and 1,000 mg/dL, because without insulin, glucose stays trapped in the bloodstream. DKA is often the first sign of undiagnosed type 1 diabetes.
Alcoholic Ketoacidosis
This form develops in people who drink heavily and then stop eating for a period, often because of nausea and vomiting. Ketone levels can reach around 15 mmol/L. A key difference from DKA: blood sugar is usually normal or even low, because the problem isn’t a lack of insulin but rather the combination of alcohol’s effects on the liver and starvation.
Euglycemic Ketoacidosis
This is a lesser-known form where blood sugar stays below 250 mg/dL, making it easy to miss. It can be triggered by fasting, surgery, pregnancy, or certain diabetes medications (particularly a class of drugs that work by causing the kidneys to excrete excess sugar in urine). People who have had bariatric surgery and have type 1 diabetes face an especially high risk, with DKA occurring in over 20% of postoperative cases.
Common Triggers
Ketoacidosis rarely happens out of nowhere. The most frequent triggers are:
- Missed insulin doses. Skipping insulin or running out of medication is one of the top causes of DKA.
- Infections and illness. Urinary tract infections, pneumonia, and other acute illnesses create stress hormones that raise blood sugar and increase insulin needs.
- New-onset diabetes. Some people don’t know they have diabetes until DKA lands them in the hospital.
- Certain medications. Steroids, some antipsychotics, and specific diabetes drugs can interfere with blood sugar regulation enough to tip the balance toward ketoacidosis.
- Substance use. Cocaine is an independent risk factor for recurrent DKA. Cannabis use also increases the likelihood of DKA in people with diabetes, partly because heavy cannabis use can cause persistent vomiting that leads to dehydration.
Symptoms and Warning Signs
Ketoacidosis symptoms often develop over 24 hours or less and tend to escalate quickly. Early signs overlap with general high blood sugar: excessive thirst, frequent urination, and fatigue. As ketone levels climb, the symptoms become more distinct and more serious.
Nausea, vomiting, and abdominal pain are common once ketoacidosis is underway. Your breath may develop a fruity or acetone-like smell, which comes from the ketones themselves. Breathing becomes deep and rapid as your lungs try to blow off excess acid. Confusion, difficulty concentrating, and drowsiness signal that the condition is becoming severe. Left untreated, ketoacidosis can lead to loss of consciousness and organ failure.
How to Check Ketones at Home
If you have diabetes, home ketone testing can catch rising levels before they become an emergency. You can test with either urine strips or a blood ketone meter. Blood meters are more accurate and give real-time results, while urine strips reflect ketone levels from a few hours earlier.
On a blood meter, a reading above 3 mmol/L is a red flag that DKA may be developing and warrants immediate medical attention. Urine strips that show three plus signs (“+++”) carry the same urgency. Testing is especially important when you’re sick, have unexplained high blood sugar, or are experiencing nausea or vomiting.
What Happens at the Hospital
Ketoacidosis treatment focuses on three things: rehydrating your body, bringing down ketone levels, and correcting the acid imbalance in your blood. You’ll receive IV fluids to replace the significant amount of water and electrolytes lost through excessive urination and vomiting. Insulin is given through an IV to stop fat breakdown and allow your cells to absorb glucose again.
Potassium levels need careful monitoring throughout treatment. Insulin drives potassium into your cells, which can cause dangerously low blood potassium if not replaced. Your medical team will check blood work frequently, often every one to two hours, to track your progress. Most people with uncomplicated DKA recover within 24 to 48 hours of starting treatment.
Survival Rates and Readmission
With proper treatment, the outlook for DKA is good. Inpatient mortality is about 0.2% for people with type 1 diabetes and roughly 1% for those with type 2. The picture is more concerning when DKA overlaps with another crisis called hyperosmolar hyperglycemic state, which pushes mortality to around 8%.
Readmission is a significant issue. Between 10% and 22% of people hospitalized for DKA end up back in the hospital within 30 days. About 40% of those readmissions are for another episode of ketoacidosis, and half of those happen within just two weeks of discharge. The most common reason for repeat episodes is difficulty accessing or consistently using insulin after leaving the hospital.