Hyperglycemia or high blood sugar

Hyperglycemia is when the sugar level in your body is above your target range. Because blood sugar targets are different for each person, it's important to talk to your doctor or nurse to find out what level is too high for you.

What causes a high blood sugar level?

Your blood sugar level may rise for many reasons. 

Common reasons your blood sugar may rise

  • Eating more food than is in your meal plan
  • Taking less diabetes medicine than you need
  • Infection or illness
  • Injury
  • Surgery
  • Emotional stress

How will I know my blood sugar levels are high?

You may feel or notice these symptoms with high blood sugar

  • Dry mouth
  • Thirst
  • Frequent urination
  • Urination during the night
  • Blurry vision
  • Drowsiness (more tired than normal)
  • Weight loss
  • Increased appetite (more hungry than normal)

What are the signs of extremely high blood sugar levels?

Symptoms of extremely high blood sugar

  • Hard time breathing
  • Dizziness when you stand up
  • Rapid weight loss
  • Loss of consciousness or coma
  • Increased tiredness or confusion

How are blood sugar levels best checked?

How to keep your blood sugar level normal

  • Test blood sugars at least four times per day: before meals and at bedtime.
  • Take your diabetes medicines as prescribed.
  • Follow your meal plan.
  • If you have Type 1 diabetes or have had diabetic ketoacidosis (DKA) before, test for urine ketones when your blood sugars are above 250 mg/dl.

Call your doctor or nurse right away if you have any of these signs

  • Your blood sugars stay high even when following your meal plan.
  • Your blood sugars stay high for 2 to 3 days. This may be a sign of illness or infection.
  • You have moderate to large urine ketones.

How can high blood sugars be prevented?

How to prevent high blood sugar

  • Follow your meal plan. Call your doctor, nurse, or dietitian if you do not think your meal plan is right for you.
  • Check your blood sugars as ordered by your doctor or nurse.
  • Take your diabetes medicines as prescribed.
  • Call your doctor or nurse when blood sugars are high for 2 to 3 days.
Last reviewed: 
January 2016

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