High blood glucose or sugar (hyperglycemia)

Please note that how you manage your or your child’s type 1 diabetes is a personal decision between you and your healthcare team. Breakthrough T1D Canada content is for informational purposes only and is not a substitute for professional medical advice. Please contact your doctor or other qualified health provider with any questions you may have regarding type 1 diabetes or any medical condition.

What is hyperglycemia?

Having too much glucose in your blood is called a ‘high’ or hyperglycemia.

The target blood glucose range for most people living with type 1 diabetes (T1D) is 3.9-10 mmol/L. Each individual should work with their endocrinologist or diabetes care team to determine their personal target range. Note that blood glucose levels can sometimes be above this target range during the two hours following meals.

Causes of a high can include:

  • Not taking enough insulin for the amount of carbs consumed through food and drinks
  • Stress
  • Illness
  • Medications (like steroids)
  • Hormonal changes, including puberty, menstruation, pregnancy, peri and post menopause
  • High intensity exercise
  • Caffeine consumption

Hyperglycemia that occurs when there is not enough insulin in the body can lead to diabetic ketoacidosis (DKA).

Signs and symptoms of long-term high blood glucose levels include:

  • Infections, including yeast infections
  • Fatigue
  • Unexplained weight loss
  • Blurred vision
  • Cuts or sores that do not heal

Persistent hyperglycemia can also contribute to long-term complications that affect the eyes, heart, kidney, and nerves.

How to treat high blood glucose

Highs are treated with insulin. Every person with T1D should have a personalized insulin plan developed in partnership with their diabetes care team. If blood glucose levels are fluctuating more than you would like, discuss with your healthcare provider to update your plan.

If blood glucose levels are  persistently high:

  • Check insulin pump or infusion site for blockages.
  • Take a correction dose of insulin.
  • Drink water and rest.
  • If levels remain high, contact your healthcare provider.
  • Check for ketones in blood or urine. If none are present, follow the steps above.
  • If ketones are trace or small, treat according to the advice provided by your diabetes care team. If ketones are moderate or large, follow the steps above and contact your diabetes care team.
  • If moderate or large ketones are present and the person has symptoms of DKA (insert new page link here), they could be in DKA or be dangerously close to it. Call their diabetes care team and emergency contact immediately. If they cannot be reached, call 911 and stay with them until emergency help arrives.

What is a correction dose?

A correction dose is insulin you take to lower blood glucose levels when it is too high. Healthcare providers will work with you to help identify the right correction dose for you or your child. This can depend on weight, length of time with T1D, type of insulins used, and how it’s administered.

Please note these are guidelines and shouldn’t be treated as medical advice. If you’re unsure what to do, please always consult with your healthcare provider or seek medical attention.

Diabetic ketoacidosis, or DKA, is a medical emergency and must be treated immediately

DKA happens when cells can’t get fuel from the sugar in your blood and break down fat instead. This creates ketones, which are acids produced in your liver and released into blood when the body breaks down fat for energy. When ketones build up, this can lead to too much acid in the blood (acidosis).

The risk for ketones and DKA is higher during illness and when insulin doses are missed, or infusion sites are occluded (blocked up preventing proper dosing). Insulin is essential to helping the body clear ketones.

Signs of DKA

  • Ketones in the urine or blood
  • Extreme exhaustion or fatigue
  • Nausea, vomiting, or abdominal pain
  • Difficulty breathing
  • Fruity odor on the breath
  • Confusion or difficulty paying attention
  • Loss of consciousness

Be prepared to check for ketones

It is important to have a way to check for ketones, either using urine test strips or blood test strips with a ketone meter.

  • Have a blood or urine ketone test kit on hand.
  • Check expiration dates on kits and discard expired test strips.
  • Read the package when there isn’t an emergency to learn how to use it. Ask your diabetes educator for support.
  • To make sure you understand the instructions, do a sample check-in consultation with your healthcare team during a clinic visit.

What are ketones?

When your body doesn’t have enough insulin to use the sugar in your blood, it breaks down fat for energy. This produces chemicals called ketones, which make your blood more acidic. Elevated ketone levels often occur when blood glucose readings are high. Very high levels could lead to diabetic ketoacidosis, or DKA, a dangerous condition that demands immediate medical attention.

Learn more about DKA and ketones.

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