Diabetic ketoacidosis is a potentially life-threatening complication of diabetes caused by a lack of insulin in the body.

It occurs when the body is unable to use blood sugar (glucose) because there isn't enough insulin. Instead, it breaks down fat as an alternative source of fuel. This causes a build-up of a potentially harmful by-product called ketones. 

Read more about the causes of diabetic ketoacidosis.

It's fairly 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.

It's important to seek medical advice quickly if you think that you or your child is experiencing the condition, because serious complications of diabetic ketoacidosis can develop if it's not treated early on.

Warning signs to look out for

If you take insulin to control your diabetes, you should keep an eye out for signs and symptoms of diabetic ketoacidosis.

Early signs and symptoms can include:

• passing large amounts of urine 
• feeling very thirsty
• feeling sick 
• abdominal (tummy) pain
• tiredness
• shortness of breath
• an increase in your blood sugar and/or ketone levels – self-testing kits are available to check these (see below)

You may become very dehydrated and if the condition isn't treated quickly, it can lead to vomiting, an increased breathing and heart rate, dizziness, drowsiness, a smell of pear drops or nail varnish on your breath, and loss of consciousness.

Read more about the symptoms of diabetic ketoacidosis.

What to do

If you think that you or your child are experiencing early symptoms of diabetic ketoacidosis, and self-testing shows you have a high blood glucose and/or ketone level, you should immediately contact your diabetes care team or GP for advice.

If this isn't possible, call your local out-of-hours service or NHS 111.

If you or someone in your care appears to be experiencing more advanced symptoms, go immediately to your nearest accident and emergency (A&E) department.

Treatment in hospital

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

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

• fluids pumped directly into a vein to rehydrate your body 
• insulin (usually pumped into a vein)  
• 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 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 and help you come up with a plan to prevent future episodes.

Read more about treating diabetic ketoacidosis. 

Be aware of the danger

If you have type 1 diabetes, you're at risk of diabetic ketoacidosis when your insulin level drops and 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.

A simple finger prick blood test can be used to detect an increase in blood sugar before it becomes a serious problem, and kits to check your ketone level are also available. You should monitor your blood sugar and ketone levels closely if you have type 1 diabetes, particularly when you're ill, so you can spot any increases early on.

Generally speaking, a blood sugar reading of 11 mmol/l or more is a sign that you're at risk of diabetic ketoacidosis and should check your ketone level if you feel ill. A ketone level reading of 2+ or more on urine strips or 0.6 mmol/l or more in your blood is a sign that you need to take immediate action to correct your levels.

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.

Read more about the causes of diabetic ketoacidosis and preventing diabetic ketoacidosis.