Diabetic ketoacidosis (high blood ketones)

Diabetic ketoacidosis (DKA) happens when your body has high blood glucose (sugar) and high ketones, which causes a build-up of acid. If it isn’t treated, it can lead to coma and even death.

On this page, you can find the following information:

Key points about diabetic ketoacidosis

  1. Diabetic ketoacidosis can become life threatening very quickly. Learn the warning signs and know when to seek emergency care (below).
  2. Causes include missed insulin doses, illness, injury, surgery, pregnancy, some medicines or too much alcohol.
  3. Warning signs include peeing lots, feeling thirsty, tiredness, tummy pain, nausea and vomiting, fruity-smelling breath, confusion or rising levels of blood sugar and ketones.
  4. Whatever your ketone level is, don’t stop taking your background insulin.
  5. To prevent diabetic ketoacidosis, always take your diabetes medicines, including insulin, follow your sick day plan if you are unwell and check with your doctor or pharmacist before starting new medicines.

Contact your doctor or diabetes nurse or go to the nearest emergency department straight away if:

  • your urine (pee) or blood ketone levels are high
  • your ketone levels are not coming down once you have started treating yourself
  • you are feeling very unwell, eg, drowsy, have rapid breathing, pain in your abdomen (tummy), nausea (feeling sick) or vomiting (being sick)
  • you are unable to look after yourself
  • you don't know how much extra insulin to take
  • you are unable to drink fluids
  • you have a temperature or an obvious sickness that is not improving.

What is diabetic ketoacidosis?

Diabetic ketoacidosis is a condition that can affect people with diabetes, usually those with type 1 diabetes. People with type 2 diabetes or diabetes in pregnancy can also have diabetic ketoacidosis but this is much rarer.

Diabetic ketoacidosis happens when your body does not have enough insulin to help it use sugar for energy. Instead, your body starts burning fat for energy, which releases harmful ketones. A build-up of ketones in your body causes your blood to become acidic. This is why it is called ketoacidosis.

Because diabetic ketoacidosis upsets the chemical balance in your body, it can quickly become dangerous. It needs immediate medical attention. It is isn't treated, diabetic ketoacidosis can lead to coma and even death. If picked up early, it can be treated with extra insulin, glucose and fluid. 

What are the causes of diabetic ketoacidosis?

Diabetic ketoacidosis usually happens to people with type 1 diabetes. It is triggered by low insulin levels, most often caused by one of the following:

  • Missed doses of insulin.
  • Insulin not being given correctly. This may be because of problems with your insulin pen, insulin cartridge or insulin pump.
  • An illness or hormonal change. Insulin in your body may not work well if you have an infection such as gastroenteritis (tummy bug), urinary tract infection, a chest infection or skin infection, or if you have stress or are pregnant. This is due to your body producing higher levels of other hormones, such as adrenaline or cortisol, which reduce the effect of insulin. 
  • An injury or surgery.

People with type 2 diabetes are at risk if they are taking empagliflozin.  

Other causes include:

  • heart attack
  • alcohol or drug abuse, in particular, cocaine
  • certain medicines, such as corticosteroids and some diuretics.

Sometimes there is no obvious cause.

What are the signs of diabetic ketoacidosis?

Signs and symptoms of diabetic ketoacidosis can include:
  • peeing lots
  • feeling very thirsty
  • dry mouth
  • dry, cool skin
  • nausea (feeling sick) or vomiting (being sick)
  • abdominal (tummy) pain, especially in children
  • tiredness, weakness, fatigue
  • shortness of breath
  • unusual or fruity-smelling breath
  • confusion
  • an increase in your blood sugar and/or ketone levels.

If you have any of the symptoms above, see your GP immediately or go to the nearest emergency department. 

How do I test for ketones?

Ketones are easy to test for. The best way is to use a blood ketone meter. If you have type 1 diabetes you can get a blood ketone meter and 2 boxes of ketone testing strips on prescription from your doctor. You can also test for ketones in your urine (pee), but this is not as accurate because it reflects your ketone levels a few hours ago rather than right now. 

Monitoring blood ketones at home allows you to find out early if you are developing ketoacidosis, so that you can give yourself insulin and potentially prevent a trip to hospital. 

When should I test for ketones?

You should test for ketones in the following situations:

  • your blood glucose is more than 15mmol/L and you have any symptoms of ketoacidosis
  • your blood glucose is over 15mmol/L twice in a row (3 hours apart) and you don’t have any symptoms
  • you feel unwell and and your blood glucose is increasing
  • you are injured and your blood glucose is increasing.

Monitoring blood glucose and ketone levels when you are sick is especially important. During minor illness or injury, blood glucose levels might increase but ketones may stay normal. However, during serious illness, such as a fever (high temperature) or infections, blood glucose AND ketone levels can both become high. Monitoring blood glucose and ketones during sickness will help you decide whether you need extra insulin.

Read more about blood glucose testing for type 1 diabetes and sick day plan and type 1 diabetes

What should I do if my ketones are raised?

Whatever your ketone levels, it's important to never stop taking your background insulin.

If your ketones are raised, adjust your insulin dose as outlined in your diabetes sick day plan. If you are unsure about how to adjust your insulin dose, contact your diabetes care provider or emergency service.

Measure your blood glucose levels and ketone levels at frequent intervals, as outlined in your diabetes sick day plan. If they remain high, contact your GP, diabetes nurse, diabetes care provider or emergency health service.

Diabetic ketoacidosis can quickly become life threatening, so it's important to get medical help as soon as possible. 

Blood ketone levels

What to do


This is a normal reading. Drink plenty of water and take your usual insulin dose at your usual time. Re-check your blood ketones again in 1–2 hours.


Contact your healthcare team. They may recommend you take an extra dose of rapid or short-acting insulin. Keep drinking plenty of water and check your ketones every 1–2 hours to make sure they are dropping.


Contact your healthcare team urgently. They may want to see you immediately or they may recommend you take additional rapid or short-acting insulin. Keep drinking plenty of water and check your ketones every hour to make sure they are dropping.

2.5–3.5mmol/L or more

If you can’t talk immediately with your healthcare team, go to the hospital now. If you are very unwell, call an ambulance on 111. Your team will recommend you take an additional dose of short or rapid-acting insulin and keep drinking plenty of water on your way to hospital.

How is diabetic ketoacidosis treated?

Diabetic ketoacidosis is a medical emergency and needs to be treated in hospital. Treatment of diabetic ketoacidosis includes:

  • insulin given through your vein
  • fluids given through a drip into your vein
  • salt and nutrients such as potassium given through your vein to replace any loss of these.

Your healthcare team will monitor you closely in the hospital to prevent complications of diabetic ketoacidosis such as:

  • too low or too high potassium levels in your blood
  • hypoglycaemia (low blood glucose) – this can be caused by insulin being given to treat diabetic ketoacidosis 
  • brain oedema (fluids in your brain)
  • pulmonary oedema (fluids in your lungs).

Your doctor or diabetes nurse specialist will find out the cause of your diabetic ketoacidosis and talk to you about your sick day management plan again.

How can I prevent diabetic ketoacidosis?

If you have diabetes, there are lots you can do to prevent diabetic ketoacidosis.

  • Take control of your diabetes. Take your medicines, including insulin, as directed. Don't skip insulin doses. If you think your insulin pen or pump may not be working properly, get it checked out.
  • Be aware of how food and exercise affect your blood glucose levels.
  • Be prepared — work with your diabetes care provider to make a sick-day plan. Know how to manage your diabetes when you are unwell, such as what your target blood glucose level should be during an illness, how often to check your blood glucose and your ketone levels, how to adjust your insulin dose or timing and when to contact your doctor for help. Read more about having a diabetes sick day plan.
  • Be careful when you start new medicines – check with your doctor or pharmacist to find out if the medicines are safe for you to take.

Learn more

The following links provide further information on diabetic ketoacidosis. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Ketones and type 1 diabetes Diabetes NZ
Diabetic ketoacidosis NHS, UK
DKA (ketoacidosis) and ketones American Diabetes Association, US 


  1. The management of diabetic ketoacidosis in adults Joint British Diabetes Societies Inpatient Care Group, UK, 2021
  2. Diabetic ketoacidosis (DKA) management Starship Clinical Guidelines, NZ, 2020
  3. Diabetic ketoacidosis Patient Info, UK

Information for healthcare providers

Best practice diabetes toolbox BPAC, NZ, 2021
Type 2 diabetes management guidance NZ Society for the Study of Diabetes and Ministry of Health, NZ, 2021
The management of diabetic ketoacidosis in adults Joint British Diabetes Societies Inpatient Care Group, UK, 2021
Diabetic ketoacidosis (DKA) management Starship Clinical Guidelines, NZ, 2020
Diabetic ketoacidosis Patient Info, UK

Dr Alice Miller trained as a GP in the UK and has been working in New Zealand since 2013. She has undertaken extra study in diabetes, sexual and reproductive healthcare, and skin cancer medicine. Alice has a special interest in preventative health and self-care, which she is building on by studying for the Diploma of Public Health with the University of Otago in Wellington.
Credits: Health Navigator Editorial Team. Reviewed By: Dr Alice Miller, FRNZCGP, Wellington Last reviewed: 19 Apr 2021