Diabetic ketoacidosis, usually shortened to DKA, is one of the most serious complications of diabetes, and it's also one of the most preventable when you know what to watch for. Understanding the warning signs, knowing when and how to check for ketones, and having a plan for sick days can help you catch trouble early and avoid a medical emergency. This guide explains what DKA is, how to recognize it, and the practical steps that help prevent it, all in plain language.
DKA Warning Signs: When to Act
According to the CDC, DKA develops when your body doesn't have enough insulin to allow blood sugar into your cells for energy, so the liver breaks down fat for fuel instead, producing acids called ketones that can build up to dangerous levels. DKA is most common in people with type 1 diabetes, but people with type 2 can develop it too. The CDC advises going to the emergency room or calling 911 right away if you have any of these signs:
- Blood sugar that stays at 300 mg/dL or above
- Breath that smells fruity
- Vomiting and being unable to keep food or drinks down
- Trouble breathing
- Multiple signs and symptoms of DKA occurring together
Other early symptoms can include excessive thirst, frequent urination, nausea, abdominal pain, fatigue, and confusion. DKA is a medical emergency, and symptoms can worsen quickly, so early recognition genuinely matters. The good news, as the American Diabetes Association emphasizes, is that DKA is often preventable with preparation and education.
Understanding Ketones and How to Test for Them
The key to catching DKA before it becomes an emergency is understanding ketones and knowing how to check them, because elevated ketones are the early warning sign that gives you time to act.
The American Diabetes Association explains that ketones develop when your body doesn't have enough insulin to use blood glucose for energy and breaks down fat instead. As ketones build up, your blood becomes dangerously acidic. Checking ketones lets you catch this process early, before it progresses to full DKA.
There are two ways to test for ketones: a blood ketone meter (which the ADA notes is the preferred method) or urine ketone strips. The ADA advises that if your blood ketone level is 1.6 mmol/L or higher, you should seek emergency medical care immediately. Research published in PubMed Central supports the blood testing approach, noting that self-monitoring of blood ketones, compared with urine testing, allows earlier identification and treatment of ketosis and can reduce diabetes-related emergency department visits and hospitalizations. Blood testing is also more accurate because urine ketone tests can lag behind what's actually happening in your blood.
The CDC recommends checking your blood sugar every 4 to 6 hours and checking for ketones when you're sick or when your blood sugar is 250 mg/dL or above. You should also test for ketones any time you have symptoms of DKA. The ADA recommends that if you're at risk for DKA, you always keep a blood ketone meter or urine ketone strips on hand, and that you check that your supplies haven't expired, since expired strips can give unreliable results.
One important note for people taking certain newer medications: the ADA points out that ketones are especially likely to develop if you take insulin, an SGLT2 inhibitor, or certain other diabetes medications. There is also a form of DKA called euglycemic DKA, where dangerous ketone buildup occurs even when blood sugar is normal or only mildly elevated. Research published in PubMed Central notes this is increasingly seen with SGLT2 inhibitor use, which is why relying on blood sugar alone isn't enough. If you take one of these medications and feel unwell, checking ketones is wise even if your glucose looks normal.
Preventing DKA: Sick-Day Basics and Daily Habits
Because DKA is largely preventable, building a few habits and having a sick-day plan in place can dramatically reduce your risk. Illness is one of the most common triggers, so preparation matters most when you're not feeling well.
Research published in PubMed Central identifies the most common triggers for DKA as infections, missed or insufficient insulin, and new-onset diabetes. This points directly to the prevention priorities: never skip your insulin (even when you're not eating much), monitor closely during illness, and act early on rising ketones.
The foundations of DKA prevention include:
- Keep taking your insulin. One of the most important sick-day rules is to continue your insulin even when you're ill and eating less. Insulin needs often rise during illness, not fall, and stopping insulin is a leading cause of DKA. Never stop insulin without guidance from your care team.
- Monitor more often when sick. Check blood sugar every 4 to 6 hours and test ketones when you're ill or when glucose is 250 mg/dL or higher.
- Stay hydrated. Drinking fluids helps your body clear excess glucose and ketones.
- Have a written sick-day plan. Work with your care team ahead of time on how to adjust insulin, when to check ketones, and when to call for help.
- Keep supplies stocked and current. Ensure you always have unexpired ketone testing supplies and enough insulin on hand.
- Don't exercise with high ketones. The ADA advises against exercising when your urine shows ketones and your blood glucose is high, as this can make things worse.
Technology can also help with early detection. A CGM like the Dexcom G7 or FreeStyle Libre 3 Plus can alert you to rising glucose early, giving you a chance to check ketones and intervene before DKA develops. Research published in PubMed Central notes that real-time CGM helps with early detection of glucose abnormalities, allowing prompt intervention. If you use an insulin pump like the Tandem t:slim X2, be especially alert to unexplained high glucose, since an infusion set failure or occlusion can interrupt insulin delivery and lead to ketone buildup relatively quickly. Our Learning Center covers pump troubleshooting in more detail.
Why Knowing About DKA Protects You
DKA is serious and can be life-threatening, but it's also one of the diabetes complications you have the most power to prevent. Knowing the warning signs, keeping ketone testing supplies on hand, continuing insulin during illness, and having a sick-day plan turn DKA from a frightening unknown into a manageable risk. The people who avoid DKA emergencies are usually the ones who caught rising ketones early and acted on them. Preparation and awareness truly are your best protection, and your diabetes care team can help you build a plan tailored to your situation. If you're ever unsure whether your symptoms warrant emergency care, err on the side of caution and seek help. At Adapt Health Diabetes, we help make sure you have the CGM and testing supplies you need to stay ahead of problems. Visit our Education page for more resources on staying safe and healthy.
Frequently Asked Questions About DKA
Can people with type 2 diabetes get DKA, or is it only type 1?
DKA is most common in people with type 1 diabetes, but people with type 2 diabetes can develop it too, particularly during serious illness, infection, or when taking certain medications. The CDC confirms that while DKA develops most often in type 1 diabetes, it is a risk for people with type 2 as well. Additionally, people taking SGLT2 inhibitor medications, which are used in type 2 diabetes, have a specific risk of euglycemic DKA, where ketones build up dangerously even with normal blood sugar. Anyone with diabetes should understand DKA warning signs regardless of their type.
When exactly should I check for ketones?
The CDC recommends checking for ketones when you're sick, when your blood sugar is 250 mg/dL or above, and any time you have symptoms of DKA. The ADA notes ketones are especially likely if you take insulin, an SGLT2 inhibitor, or certain other medications. During illness, checking every 4 to 6 hours along with your blood sugar is a common recommendation. If you take an SGLT2 inhibitor, checking ketones when you feel unwell is wise even if your glucose is normal, because of the risk of euglycemic DKA. Your care team can give you personalized guidance on your specific thresholds.
What's the difference between blood ketone testing and urine ketone testing?
Both detect ketones, but blood ketone testing (using a blood ketone meter) is the preferred method because it's more accurate and detects ketones earlier. Urine ketone strips are affordable, widely available over the counter, and still useful, but they can lag behind what's actually happening in your blood, since urine reflects ketone levels from earlier. Research shows blood ketone testing allows earlier identification of ketosis and can reduce emergency visits. If you're at risk for DKA, keeping either type on hand is important, but a blood ketone meter offers the earliest warning. Make sure your supplies haven't expired.
Why shouldn't I stop taking insulin when I'm sick and not eating?
This is one of the most important and counterintuitive sick-day rules. Even when you're not eating much, your body still needs insulin, and illness often increases your insulin needs rather than decreasing them. Stopping insulin during illness is a leading cause of DKA, because without insulin your body starts breaking down fat and producing ketones. Instead of stopping insulin, you should monitor more closely and follow your care team's sick-day plan, which may actually involve adjusting your dose. Never stop your insulin without specific guidance from your healthcare provider.
Can an insulin pump increase my risk of DKA?
Pump users need to be aware that because pumps use only rapid-acting insulin with no long-acting backup, any interruption in delivery (from an occlusion, a kinked cannula, a dislodged infusion set, or an empty reservoir) can lead to rising glucose and ketones relatively quickly. This is why unexplained high glucose in a pump user should prompt a check of the infusion site, a possible site change, and ketone testing. It's not a reason to avoid pump therapy, which offers many benefits, but it does mean staying alert to unexplained highs and knowing how to respond. Keeping backup insulin and supplies on hand is always recommended for pump users.
Stay Prepared With Reliable CGM and Testing Supplies
Catching problems early starts with having the right tools on hand. Adapt Health Diabetes delivers Dexcom and Abbott FreeStyle Libre CGM supplies through your insurance on a reliable schedule, helping you monitor your glucose and stay ahead of trouble. Visit our Resources page for more information, or contact our team with questions about your supplies.
This article is for educational purposes only and does not replace professional medical advice. DKA is a medical emergency. If you have symptoms of DKA, seek emergency medical care immediately. Always work with your healthcare provider to develop a sick-day plan and ketone monitoring guidance tailored to your situation.
Sources
- Centers for Disease Control and Prevention. Diabetic Ketoacidosis. CDC Diabetes. 2025.
- American Diabetes Association. DKA (Ketoacidosis) and Ketones. ADA.
- Dhatariya KK, et al. Diabetic Ketoacidosis: Update on Management. PubMed Central. 2019.
- Long B, et al. Euglycemic Diabetic Ketoacidosis: Clinical Suspicion and Diagnosis. PubMed Central. 2025.
