Ketones and Diabetes


What are ketones?

Ketones are produced when the body ‘burns’ some of its own fat for fuel. This happens when the body cannot utilise the glucose in the blood to meet its energy needs.

Why should you be aware of ketones?

Insulin is a hormone produced in the pancreas that helps the body to use glucose as an energy source. As people with diabetes do not produce insulin, or their insulin doesn’t work as it should, the body may have to start burning fat for energy in situations where glucose isn’t being used, and this produces ketones. The presence of ketones in the bloodstream is therefore a possible complication of diabetes. If left untreated, this can result in a condition called diabetic ketoacidosis (DKA). Blood becomes acidic which is a serious problem that can lead to diabetic coma.

How can I prevent ketone build up?

There are a number of things that you can do to help prevent raised ketone levels and DKA:

Eat sensibly and regularly

If you regularly skip meals, particularly carbohydrate based ones, your body will naturally start to produce ketones. A sensible mixed diet with a regular source of starchy or ‘complex’ carbohydrates will help to prevent the production of ketones.

Preferred carbohydrates

Starch and sugars are both types of carbohydrate. Starchy or ‘complex’ carbohydrates are the preferred source of energy in the diet of people with diabetes, such as:

  • Whole grain cereals
  • Vegetables
  • Beans
  • Nuts
  • Wholemeal bread
  • Brown rice
  • Potatoes
  • Pasta

Maintain your diabetes therapy

It may sound obvious, but be sure to stick to the treatment plan prescribed by your doctor, using insulin and/or taking your oral medication as instructed. Poor glucose control contributes to ketone production, so make sure you regularly check your blood glucose and let your doctor or nurse know if it is outside your target range.

Take regular exercise

Regular exercise is good, but build up gradually and make sure your body has enough carbohydrates to meet your energy needs. Fat will be broken down and ketones produced in the absence of adequate carbohydrates during sudden exercise.

Take extra care during illness

If you don’t feel like eating when unwell, try to match your normal carbohydrate intake with milk, fruit juice or glucose drinks. As illness may affect your diabetes therapy, carefully monitor your blood glucose and report any changes to your doctor or nurse.

If you start vomiting - particularly if you have high blood glucose, are passing a lot of urine, feel cold and have rapid breathing - seek medical advice immediately, as these symptoms could be due to DKA.

Monitor your ketone levels

Ketone monitoring is particularly important for:

  • People with type 1 diabetes, as they are more likely to develop ketones than those with type 2. Everyone with type 1 diabetes should regularly test for ketones in their urine if advised by their healthcare professional
  • Women with type 1 or 2 diabetes who become pregnant.
  • Women with gestational diabetes
  • People with type 2 diabetes who are taking medication or using insulin to treat their condition and have been advised by their healthcare professional

How do I test for ketones?

Your healthcare professional will advise you on exactly how and when to check your ketone levels, but simple dip-and- read urine test strips (e.g. KETOSTIX®) are the most common method for home testing. These change colour when dipped into a urine sample containing ketones. Bottles of 50 KETOSTIX® reagent strips are available on prescription and also without prescription from your local pharmacy.

What should I do if I test positive for ketones?

  • Drink half a pint (250 ml) of sugar-free liquid every hour
  • Follow the sick-day management advice that your diabetes care team has given you
  • Check your blood glucose and urinary ketones regularly
  • Do NOT exercise if your blood glucose level is above 15 mmol/L and ketones are present in your urine

What are the warning signs of diabetic ketoacidosis (DKA)?

DKA usually develops slowly, but when vomiting occurs, this life-threatening condition can occur within a few hours.

Early symptoms include:

  • Thirst or a very dry mouth
  • Frequent urination
  • High blood glucose
  • High levels of ketones in the urine
  • Other symptoms then appear:
  • Constant tiredness
  • Dry or flushed skin
  • Nausea, vomiting or abdominal pain
  • Short, deep breaths
  • Confusion or difficulty paying attention
  • Fruity-smelling ‘pear drop’ breath
  • Blurred vision

It should be noted that many of these symptoms can be cause by a range of illnesses, not just ketoacidosis. If vomiting continues for more than 2 hours however, seek medical assistance without delay.

Top Tips

  • If you test positive for ketones and things don’t improve after following the advice on this page - seek help
  • If you are at all unsure about what to do, contact your diabetes care team for advice
  • Make sure that your ketone test strips are in date
  • Always keep ketone test strips in their original container with the lid tightly shut, as they are sensitive to light and moisture
  • Do not stop taking your insulin or oral diabetes medicines unless told to do so by your doctor


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