Complications of diabetic ketoacidosis 

With prompt treatment, diabetic ketoacidosis can be corrected without any complications developing. If left untreated, the condition can be life-threatening. 

Certain groups of people are more likely to develop serious problems from diabetic ketoacidosis. These include young children, elderly people, and those with another serious underlying condition.

Some of the main complications of diabetic ketoacidosis are described below.


If you're urinating a lot and vomiting because of diabetic ketoacidosis, you're likely to become dehydrated and lose important minerals, such as potassium.

If your potassium levels fall to a dangerously low level, it's known as hypokalaemia. This is one of the main causes of deaths in adults with diabetic ketoacidosis.

Hypokalaemia can cause a number of problems, some of which can be very serious. These include:

  • weakness and fatigue
  • muscle cramps
  • constipation
  • breathing difficulties
  • an abnormal heart rhythm (arrhythmia)

Hypokalaemia occurring with diabetic ketoacidosis usually needs to be treated by giving extra potassium in hospital via a drip into a vein.

A reduction in potassium levels can also occur after insulin treatment in hospital, but you will be closely monitored for this and given extra potassium if necessary.

Acute kidney failure

Severe dehydration can cause your kidneys to stop working (acute kidney failure).

Your kidneys remove waste products from your blood, so if they stop working you may experience a range of symptoms, such as:

  • swelling in your arms and legs caused by a build-up of fluid (oedema)
  • feeling sick
  • feeling very tired
  • confusion

Until your dehydration has been successfully treated, you may need dialysis, where a machine filters waste products from your blood.

Once your fluid levels have been restored to normal, your kidneys should start to recover.

Cerebral oedema

In up to 1% of cases, a very serious complication called cerebral oedema can occur. This is where excess fluid builds up inside the brain.

It's most often seen in children and young adults, and is the leading cause of death in people with diabetic ketoacidosis in this age group. Around one in every four cases is fatal.

Symptoms of cerebral oedema include:

  • headache
  • drowsiness
  • restlessness and irritability
  • facial paralysis (palsy)
  • seizures (fits)

A person with cerebral oedema will be admitted to an intensive care unit (ICU) and treated with a medication called mannitol, which helps to reduce the swelling of the brain.

Acute respiratory distress syndrome

The rapid and unpredictable changes in fluid levels that can occur in diabetic ketoacidosis can occasionally result in the lungs becoming filled with fluid.

This is known as acute respiratory distress syndrome (ARDS) and can cause serious breathing difficulties.

If you develop ARDS, a ventilator can be used to help you breathe until your condition stabilises.

Page last reviewed: 23/04/2015

Next review due: 23/04/2017