Hyperglycaemia, otherwise known as a blood glucose level (BGL) above your target range, occurs when glucose levels rise above 15mmol/L.

This can develop over many hours or days.

In some cases your glucose levels can be high without you knowing. 

It is normal for blood glucose levels to fluctuate and sometimes be above your target range. An occasional glucose level above target is not a concern. However if this is happening frequently or if your blood glucose levels stay elevated over several hours it might be time to check in with your diabetes health care team.

Hyperglycaemia occurs in the lead up to diagnosis or can be caused by one or a number of the following events

Symptoms will vary from person to person, and may include:

  • Not enough insulin or other glucose lowering medication
  • A larger than normal meal or snack
  • Inaccurate carbohydrate counting or inaccurate insulin to carbohydrate ratio
  • Stress or anxiety
  • Illness
  • Some medications e.g. steroid medications

Symptoms of hyperglycaemia can include

  • No symptoms at all
  • Feeling very thirsty
  • Going to the toilet more often (large volumes of urine)
  • Feeling tired
  • Blurred vision
  • Infections (e.g. thrush, wound infections)
  • Weight changes

Managing hyperglycaemia in type 2 diabetes

An occasional elevated blood glucose level is not a major concern.

However if your blood glucose levels remain elevated over several hours or days or if you are feeling any of the symptoms mentioned above, it is important to see your GP or Credentialled Diabetes Educator for a review.

In the meantime it is important to stay hydrated if your blood glucose levels are elevated, so aim to drink plenty of water (unless you are on a fluid restriction, in which case see your GP as soon as possible).

If you are unwell, see the following page for more information on managing diabetes when you are sick.

Managing hyperglycaemia in type 1 diabetes

Follow your sick day management plan if you have one.  

If you do not have a sick day management plan or if you are noticing frequent elevated glucose levels and are unable to pinpoint the cause, contact your doctor or Credentialled Diabetes Educator for advice on adjusting your insulin doses.

Check your blood glucose levels frequently and monitor blood ketone levels (or urine ketone levels if unable to check blood ketones).

Drink extra fluid where possible, when BGLs are elevated aim to include more water or sugar free fluids.

In type 1 diabetes, hyperglycaemia can lead to diabetic ketoacidosis (DKA). DKA occurs when there is not enough insulin available and glucose is unable to get into the cells to be used for energy. Instead the body starts to breakdown fats for energy, this process produces ketones which are toxic if they build up in the blood. This can also occur when blood glucose levels increase due to illness. DKA is very serious and needs to be treated urgently in hospital.

Symptoms of DKA include:

  • Abdominal pain
  • Nausea and vomiting
  • Deep, fast breathing
  • Drowsiness or loss of consciousness
  • Fruity smelling breath

If you or a loved one are experiencing these symptoms or are monitoring ketone levels at home and find they are high or increasing, seek medical attention immediately.