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Hyperglycaemia and diabetes

Hyperglycaemia is also known as high blood sugar, or high blood glucose, and can be a serious problem for a person with diabetes.

Hyperglycaemia happens when the body is unable to remove glucose from the blood and turn it into energy.

Short-term symptoms of hyperglycaemia include increased thirst, wanting to urinate more often, and feeling tired. In the longer term, untreated hyperglycaemia can cause blurred vision and unexpected weight loss.

The symptoms of hyperglycaemia can often lead to a diagnosis of diabetes, or in a person already diagnosed with diabetes it can be a sign that the condition is not well managed.

In fasting hyperglycaemia, blood sugar is still high after fasting for at least 8 hours.

In postprandial or hyperglycaemia after a meal, blood sugar becomes high after eating and drinking.

What causes hyperglycaemia in diabetes?

Hyperglycaemia in diabetes may be caused by:

  • Skipping or forgetting your insulin or oral glucose-lowering medication
  • Eating too many grams of carbohydrates for the amount of insulin administered or just eating too many grams of carbohydrates in general
  • Infection
  • Illness
  • Increased stress
  • Decreased activity or exercising less than usual
  • Strenuous physical activity

What are the symptoms of hyperglycaemia in diabetes?

If you have diabetes, it is important to know the early signs of hyperglycaemia. If hyperglycaemia is left untreated, it may develop into ketoacidosis (if you have type 1 diabetes) or HHNS (if you have type 2 diabetes), both of which are serious emergencies.

Early signs of hyperglycaemia in diabetes include:

  • Increased thirst
  • Headaches
  • Difficulty concentrating
  • Blurred vision
  • Frequent urination (especially at night)
  • Fatigue (weak, tired feeling)
  • Weight loss and loss of muscle bulk
  • Blood sugar more than 10 mmol/l

Prolonged hyperglycaemia in diabetes may result in:

  • Vaginal and skin infections
  • Slow-healing cuts and sores
  • Decreased vision
  • Nerve damage causing painful cold, or insensitive feet, loss of hair on the lower extremities, and/or erectile dysfunction
  • Stomach and intestinal problems such as chronic constipation or diarrhoea

How is hyperglycaemia in diabetes treated?

If you have diabetes and have any of the early signs of hyperglycaemia, be sure to test your blood sugar several times. You will need to have a record of several blood sugar readings. Your GP may recommend the following changes:

  • Increase your dose of insulin
  • Exercise more - exercise will help to lower your blood sugar.
  • Change your eating habits - you may need to meet with a dietitian to change the amount and types of foods you are eating.
  • Change your medication - your GP may change the amount, timing or type of diabetes medication you take.

Do not make adjustments in your diabetes medication without first talking with your GP, diabetes nurse or other member of your diabetes care team.

Your doctor may want you to test your urine for ketones.

Seek medical advice if your blood sugar is consistently greater than the level your doctor or diabetes specialist nurse has advised you it should be.

How can hyperglycaemia in diabetes be prevented?

To prevent hyperglycaemia in diabetes, make sure you are working to meet the HbA1c targets set by your diabetes care team by taking medication as recommended and following diet and exercise advice.

  • Know your diet, and if recommended, count the total amounts of carbohydrate that you are eating.
  • Test your blood sugar regularly.
  • Know when to seek medical advice if you have repeated abnormal blood sugar readings.
  • Make sure you always wear medical identification that states you have diabetes so you can receive correct treatment in the event of an emergency.
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WebMD Medical Reference

Medically Reviewed by Dr Rob Hicks on October 27, 2017

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