DKA: what to know

Diabetic ketoacidosis (DKA) is a serious but preventable emergency. Learn what causes it, the warning signs, how to check ketones, what the numbers mean, and when to call 9-1-1.

6 min read · last reviewed October 3, 2026

Diabetic ketoacidosis, or DKA, is one of the most serious short-term problems in type 1 diabetes. It can make you very sick, very quickly. But here's the important part: most DKA can be prevented, and when it's caught early, it can be treated. Knowing the signs, and what to do, is one of the best ways to keep yourself safe.

What is DKA?

Your body needs insulin to move sugar from your blood into your cells for energy. When there isn't enough insulin, your cells can't use that sugar, so your body starts breaking down fat for fuel instead. This makes acids called ketones.

A few ketones are harmless. But when they build up quickly, your blood becomes too acidic. Your body also loses a lot of water through peeing, so you become dehydrated. That combination is DKA. Without treatment, it can be life-threatening.

DKA mostly happens in type 1 diabetes, but it can also happen in people with type 2 diabetes, especially those taking insulin or medicines called SGLT2 inhibitors.

What causes DKA?

The most common triggers are:

• Missed or not enough insulin. For example, forgetting doses, running out, or reducing insulin because you're not eating.
• Illness or infection, such as the flu, a stomach bug or a bladder infection. Illness raises stress hormones, which push blood sugar and ketones up.
• A pump problem. If your pump stops delivering insulin (a kinked tube, a blocked site, a dislodged cannula or an empty reservoir), ketones can start rising within a few hours, because there's no long-acting insulin in your body.
• Insulin that has gone bad, from heat or freezing.
• SGLT2 inhibitors. These medicines can cause DKA even when blood sugar is only a little high, or normal.
• Sometimes, DKA is how type 1 diabetes is first found.

Warning signs

DKA usually develops over hours to a day. Early signs:

• very high blood sugar
• feeling very thirsty, and peeing a lot
• feeling tired or weak

Later, more serious signs:

• feeling sick, throwing up
• stomach pain
• breath that smells fruity (like nail polish remover)
• deep or fast breathing
• feeling very sleepy, confused or hard to wake

Something you can do today: Put this list on your fridge, and share it with the people you live with.

Checking for ketones

Ketone checks are your early warning system. You can check with:

• Blood ketone strips in a meter that reads ketones. These are the most accurate and show what's happening right now. Many guidelines prefer them.
• Urine ketone strips. These are cheaper but show what was happening a few hours ago.

When to check: Diabetes Canada suggests checking for ketones if your blood sugar stays above 14 mmol/L (about 250 mg/dL) for more than a few readings. Also check whenever you're sick, throwing up, or have symptoms of DKA, whatever your blood sugar. If you take an SGLT2 inhibitor, check if you feel unwell, even if your sugar looks normal.

What do blood ketone numbers mean?

Your team will give you your own plan. As a general guide:

• Below 0.6 mmol/L: normal. Keep following your usual plan.
• 0.6 to 1.5 mmol/L: slightly high. Follow your sick-day plan: extra fluids, and extra insulin if your team has told you how. Re-check in 1 to 2 hours.
• 1.5 to 2.9 mmol/L: high, and you're at risk of DKA. Call your diabetes team now and follow your sick-day plan.
• 3.0 mmol/L or higher: very high, and DKA is likely. Go to emergency or call 9-1-1.

For urine strips, moderate or large ketones mean call your team now. Large ketones with symptoms mean get emergency help.

What to do if your ketones are up

• Keep taking your insulin. Never stop your basal insulin. You may need extra rapid-acting insulin. Follow your sick-day plan.
• Drink sugar-free fluids, about a cup (250 mL) every hour if you can.
• If you use a pump and your blood sugar is high with ketones, assume the pump may not be working. Give a correction dose by pen or syringe, change your infusion set and site, and follow your team's plan.
• Re-check your blood sugar and ketones every 1 to 2 hours.
• Don't exercise when your blood sugar is high and you have ketones. It can make things worse.

When to call 9-1-1 or go to emergency

• You're throwing up and can't keep fluids down
• Blood ketones are 3.0 mmol/L or higher
• You have stomach pain, fruity breath, or deep or fast breathing
• You're confused, very sleepy or getting worse
• You aren't sure what to do and you can't reach your team

Don't drive yourself. In hospital, DKA is treated with fluids, insulin and minerals such as potassium, given through an IV. Most people recover fully.

Preventing DKA

• Never skip your basal insulin, even when you're not eating.
• Have a written sick-day plan, and keep blood ketone strips at home (check the expiry date).
• If you use a pump, always carry backup pens or syringes, and know your backup basal dose.
• Store insulin properly, and never use insulin that has been frozen or overheated.
• Don't run out. Refill your insulin and supplies early.
• Tell your team if you've had DKA before, or if paying for insulin or supplies is a problem.

Something you can do this week: Check that you have unexpired blood ketone strips and a written sick-day plan.

Questions to ask your care team

• When should I check my ketones? Which strips should I use?
• How much extra insulin should I take if my ketones are high?
• What's my backup plan if my pump stops working?
• Should I avoid any medicines because of the risk of DKA?
• When should I call you, and when should I go to emergency?

This article is general information, not medical advice. Talk with your health care team about your own situation. In an emergency, call 9-1-1 or your local emergency number.

In an emergency, call 9-1-1 or your local emergency number.

General information, not medical advice. It does not replace your own care team. If you think you or someone else is having a medical emergency, call 9-1-1 or your local emergency number. If you are in crisis or thinking about suicide, call or text 9-8-8 (Canada and the US).

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