Diabetic ketoacidosis

Diabetic ketoacidosis is a potentially life-threatening complication of diabetes caused by a lack of insulin in the body. It's important to seek medical advice quickly if you think that you or your child is experiencing the condition.

Causes of diabetic ketoacidosis 

Diabetic ketoacidosis is a complication of diabetes that can occur if the body starts to run out of insulin.

It's common in people with type 1 diabetes and can very occasionally affect those with type 2 diabetes. It sometimes develops in people who were previously unaware they had diabetes. Children and young adults are most at risk.

Insulin enables the body to use blood sugar (glucose). If there is a lack of insulin, or if it can't be used properly, the body will break down fat instead.

The breakdown of fat releases harmful, acidic substances called ketones.The lack of insulin in your body leads to high blood glucose levels (hyperglycaemia).

The combination of high ketone and blood sugar levels can cause a number of symptoms that can be very serious if the levels aren't corrected quickly. 

Symptoms of diabetic ketoacidosis  

The initial symptoms of diabetic ketoacidosis can develop quite suddenly. They will continue to get worse if not treated.

Early symptoms

In the early stages, the main signs of diabetic ketoacidosis include:

You may also develop other symptoms of dehydration, such as a dry mouth.

If you have your own device or kit to measure your blood sugar and/or ketone levels, you may notice that the levels of both of these are higher than normal.

Advanced symptoms

Left untreated, more advanced symptoms can develop, including:

  • rapid heartbeat (tachycardia)
  • rapid breathing, where you breathe in more oxygen than your body actually needs (hyperventilate) 
  • vomiting
  • dizziness
  • a smell of ketones on your breath, which can smell like pear drops or nail varnish remover 
  • confusion
  • drowsiness or loss of consciousness (coma)

In some cases, life-threatening complications of diabetic ketoacidosis can also develop.

When to seek medical advice 

You should contact immediately your GP for advice if:

  • you think you or your child are experiencing early symptoms of diabetic ketoacidosis
  • and, if you have blood self-testing equipment, self-testing shows you have a high blood glucose and/or ketone level

If your GP surgery is closed, call the GP out of hours service.

If you or someone in your care appears to be experiencing more advanced symptoms, go immediately to your emergency department.

Treatment for diabetic ketoacidosis 

In most cases, people with diabetic ketoacidosis will need to be treated in hospital.

While in hospital, you'll usually receive a combination of:

  • fluids directly into a vein to rehydrate your body 
  • insulin
  • replacement of minerals you may have lost, such as potassium

You'll be closely monitored to check how well you're responding to treatment.

As long as there are no further problems, you should be able to leave hospital when you're well enough to eat and drink normally; and when tests show a safe level of ketones in your body.

Before being discharged from hospital, a diabetes nurse will talk to you about why you developed diabetic ketoacidosis to help you prevent it happening again.

Be aware of the risk  

If you have type 1 diabetes, you're at risk of diabetic ketoacidosis when your:

  • insulin level drops
  • your blood sugar level starts to rise (hyperglycaemia)

This often occurs when you're ill with an infection such as flu or a urinary tract infection (UTI), as this causes the body to release extra hormones into your blood to help combat the illness.

These hormones interfere with the effect of insulin, meaning that you need more insulin.

It can also occur if you don't have enough insulin because you aren't following your recommended treatment plan correctly, or you haven’t adjusted your dose of insulin to take account of rising blood sugars when you have an infection.

A simple finger prick blood test can be used to detect an increase in blood sugar before it becomes a serious problem.

Kits can also check the level of ketones in urine. You should monitor your blood sugar and ketone levels closely if you have type 1 diabetes, particularly when you're ill. This means you can spot any increases early on.

Adjusting your insulin dose as advised by your diabetes care team will often correct your blood sugar and ketone levels, preventing diabetic ketoacidosis.

Seek medical advice if your levels remain high after taking insulin or you develop the symptoms mentioned above.


The information on this page has been adapted from original content from the NHS website.

For further information see terms and conditions.

This page was reviewed December 2017

This page is due for review August 2020

Health conditions A to Z

Search by health condition or symptoms

Or find conditions beginning with …

Share this page


Your comments are anonymous and can’t be responded to - if you would like a reply, use the feedback form.

Your comments
Plain text only, 750 characters maximum. Don't include personal or financial information.