Diabetic ketoacidosis (DKA) happens when your body doesn’t have enough insulin to move sugar from your blood into your cells for energy. Without that insulin, your body starts breaking down fat at a dangerous pace, producing acidic compounds called ketones that build up in your blood and make it dangerously acidic. The most common triggers are infections, missed insulin doses, and insulin delivery problems, but several less obvious causes can set it off too.
How DKA Develops in the Body
Insulin does more than lower blood sugar. It also acts as a brake on fat breakdown. When insulin drops too low, that brake releases, and your fat cells start flooding the bloodstream with fatty acids. Your liver converts those fatty acids into ketone bodies, which are an alternative fuel source your cells can use in a pinch. The problem is that ketones are acidic, and when they accumulate faster than your kidneys can clear them, your blood pH drops below safe levels.
At the same time, stress hormones like cortisol and adrenaline surge, pushing your liver to dump even more glucose into your blood. Glucagon, a hormone that normally counterbalances insulin, accelerates both the rise in blood sugar and the production of ketones. The result is a dangerous combination: high blood sugar pulling water out of your cells (causing severe dehydration), plus acidic blood that disrupts how your organs function. This entire process can unfold in less than 24 hours.
Infection Is the Leading Medical Trigger
Infections account for roughly 40% of DKA episodes. When your body fights an infection, it releases stress hormones that raise blood sugar and increase your insulin needs. If your usual insulin dose suddenly isn’t enough to keep up, the cascade toward ketoacidosis can begin quickly. Urinary tract infections, pneumonia, and skin infections are among the most common culprits, but any illness that triggers inflammation, from the flu to a dental abscess, can do it.
This is why “sick day” management matters so much for people with diabetes. The CDC recommends checking your blood sugar every four hours when you’re ill and testing your urine for ketones with an over-the-counter kit. You should keep taking your insulin as prescribed during illness, even if you’re not eating much. Your body’s insulin needs typically go up, not down, when you’re fighting off an infection.
Missed Insulin and Delivery Problems
The single most common cause of DKA overall is simply not getting enough insulin. In one study of adults with type 1 diabetes, insulin non-adherence (missing one or more doses in the week before hospitalization) was the precipitating factor in 51.2% of DKA cases. Sometimes this is unintentional: a vial expires without anyone noticing, a dose gets skipped during a busy day, or financial barriers make insulin hard to afford consistently. In that same study, 72% of participants admitted they never checked their insulin’s expiration date.
For people using insulin pumps, a separate set of risks emerges. Among pump users hospitalized with DKA, 55% had a pump or tubing defect, most often kinks or air bubbles that silently blocked insulin delivery. Half of those patients admitted to leaving their infusion site in place longer than the recommended two to three days, which can cause absorption problems. And 90% of pump users admitted with DKA had been skipping their mealtime insulin boluses. Because pumps deliver tiny, continuous doses, any interruption in delivery can lead to DKA much faster than it would with injections, sometimes within just a few hours.
Knowledge gaps play a role too. Only about 35% of participants in that study knew how to manage high blood sugar during sick days or how to prevent DKA, suggesting that many people with diabetes never receive adequate education on this specific risk.
New-Onset Diabetes
DKA is sometimes the first sign that someone has diabetes at all. This is especially common in type 1 diabetes, where the immune system destroys insulin-producing cells. A person, often a child or young adult, may have been losing weight and feeling increasingly thirsty for weeks without realizing anything is seriously wrong. By the time symptoms become severe enough to prompt an emergency room visit, they’re already in full ketoacidosis. For a parent or family member, recognizing the early pattern of excessive thirst, frequent urination, unexplained weight loss, and fatigue can make the difference between a routine diagnosis and a life-threatening emergency.
Medications That Can Trigger DKA
A class of diabetes drugs called SGLT2 inhibitors (brand names include Farxiga, Jardiance, and Invokana) can cause a particularly tricky form of DKA where blood sugar stays below 250 mg/dL. This is called euglycemic DKA, and it’s dangerous precisely because the normal warning sign of very high blood sugar is missing.
These drugs work by forcing your kidneys to excrete excess glucose into your urine. That sounds helpful, but the loss of glucose creates a state resembling starvation from your body’s perspective, even if you’re eating normally. Your pancreas releases more glucagon and less insulin in response, tipping the balance toward fat breakdown and ketone production. The drugs also directly stimulate glucagon release and reduce your kidneys’ ability to clear ketones from the blood. Situations that increase the risk include surgery, prolonged fasting, heavy alcohol use, or a significant reduction in carbohydrate intake while on these medications.
Corticosteroids like prednisone can also push someone toward DKA by dramatically raising blood sugar and increasing insulin resistance. Other medications, including certain antipsychotics and high-dose thiazide diuretics, can have similar effects in vulnerable individuals.
Other Contributing Factors
Several other situations can trigger DKA, often by raising stress hormones or increasing insulin demand beyond what the current dose can handle:
- Heart attack or stroke: The massive stress response floods the body with hormones that spike blood sugar.
- Heavy alcohol use: Alcohol impairs the liver’s ability to regulate glucose and can mask early symptoms of DKA like nausea and confusion.
- Substance use: Cocaine and methamphetamine trigger surges in stress hormones that raise blood sugar rapidly.
- Surgery or trauma: Physical stress from any major injury or surgical procedure increases insulin requirements.
- Pregnancy: Hormonal changes in the second and third trimesters can significantly increase insulin resistance.
Recognizing the Warning Signs
DKA symptoms can escalate from manageable to dangerous within 24 hours. The earliest signs overlap with general high blood sugar: excessive thirst, frequent urination, and fatigue. As ketones rise, nausea, vomiting, and abdominal pain set in. Your breath may develop a fruity or acetone-like smell, which is the scent of ketones being exhaled. Breathing becomes deep and rapid as your lungs try to compensate for the acid in your blood. Confusion and drowsiness are late signs that indicate the situation is becoming critical.
If your blood sugar reads above 300 mg/dL on more than one check, or if a urine ketone test shows moderate to high levels, those are signals that DKA may be developing. For people on SGLT2 inhibitors, testing for ketones is especially important when you feel unwell, since your blood sugar alone won’t tell the full story.
Why DKA Mortality Is Rising
Despite being a well-understood and treatable condition, DKA-related deaths in the United States have been increasing. Between 1999 and 2022, there were over 40,000 DKA-related deaths nationwide. The age-adjusted mortality rate climbed 32.6% when comparing 2003 to 2012 against 2013 to 2022. The years following the start of the COVID-19 pandemic saw a notable jump, with mortality rates of 1.67% to 1.81% in 2020 through 2022, compared to 1.23% in 2019. Disrupted healthcare access, delayed treatment, and the metabolic effects of COVID-19 itself all likely contributed.
These numbers reinforce that DKA remains a serious, potentially fatal complication. The most effective prevention is consistent insulin delivery, prompt attention to illness, and knowing how to check for ketones before a bad day becomes a medical emergency.