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Diabetes - Management of High Blood Glucose (Hyperglycemia)

What is Hyperglycemia?

Hyperglycemia is known as "high blood glucose (sugar)". It is a condition in which the amount of  glucose in the blood is higher than normal. It occurs when your body does not produce enough insulin or use insulin properly.

Insulin is a hormone secreted in the pancreas that allows your cells to use glucose for energy.

What Causes High Blood Glucose?

There are many causes of hyperglycemia.

Common causes are:

  • Missing a dose of medication
  • Taking an incorrect dose of medication
  • Using insulin incorrectly (wrong dose, expired insulin, wrong technique)
  • Not following meal plans
  • Underlying illness or infection
  • Being less active than usual

Other causes include:

  • Drinking excessive alcohol
  • Drugs (e.g. steroid)
  • Over-treating of low blood glucose

Symptoms of Hyperglycaemia

Hyperglycemia 1.png

Try keeping a record of all the food and drinks you consume throughout the day. Check your blood sugar levels according to your doctor's recommendations.

How Does High Blood Glucose Affect Your Body?

High blood glucose occurs when diabetes is not managed properly.

This can lead to diabetes-related complications such as:

  • Damage to blood vessels, resulting in conditions such as heart attack and stroke
  • Damage to the eye
  • Damage to kidneys
  • Damage to the nerves
  • Skin infections

Understanding Your Blood Glucose Level

​Before Food
(mmol/L)
​2hrs After Food
(mmol/L)
​​Good​4.0 to 6.0​5.0 to 7.0
​Optimal​6.1 to 8.0​7.1 to 10.0
​Sub-optimal​8.1 to 10.0​10.1 to 13.0
​Unacceptable​>10.0​>13.0

A reading in the "Unacceptable" range indicates that your blood glucose level is too high.

What Should You Do if Your Blood Glucose Level is High?

  • Drink more water as instructed by your doctor
  • Check your blood glucose every 4 to 6 hours
  • Avoid consuming sugary beverages
  • Visit a doctor if you have an infection or feel unwell
  • Inform your doctor or nurse to make adjustments to your medication(s) if steroids  drugs are needed
  • Take extra fast-acting insulin if this has been instructed by your doctor
  • Stay physically active
  • Reduce stress
  • Avoid alcohol intake


High blood glucose if left untreated for a long period of the time can lead to a life-threatening condition called Diabetic Ketoacidosis or Hyperosmolar Hyperglycemia, which requires hospitalisation.

Seek Medical Attention IMMEDIATELY if You Have:

  • Recurrent episodes of high blood glucose (>13mmol/L) or ketones are persistently present or >1.5mmol/L
  • Persistent nausea and vomiting
  • Persistent diarrhoea
  • Stomach pain
  • Feeling lethargic
  • Confusion
  • Shortness of breath
  • Very dry mouth or unable to maintain hydration
  • A 'fruity odour' to your breath


Call your Diabetes Nurse Educator or your doctor if you have persistent high blood glucose levels

How to Prevent High Blood Glucose

Hyperglycemia 2.png

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2020/10/08
2020/11/04
Last Updated on