Hyperglycemia is defined as blood glucose (sugar) levels that are higher than the target values for the majority of people with diabetes:

1. above 7 mmol/L fasting or before a meal
2. above 10 mmol/L two hours after a meal

Hyperglycemia occurs when the amount of insulin in the blood is insufficient or ineffective. When glucose circulating in the blood cannot enter the cells because of a lack of insulin, it accumulates in the blood and raises a person’s glycemia (blood glucose levels) .

Symptoms

Some people may not notice their hyperglycemia. However, above a certain threshold, high blood sugar can lead to the following symptoms:

• drowsiness
• increased urination
• intense thirst
• excessive hunger
• involuntary weight loss
• irritability
• dizziness

Causes

The primary causes of hyperglycemia are:

• a diet abnormally high in carbohydrates
• reduced physical activity
• insufficient insulin  and/or antidiabetic medication (dosage error or a skipped dose)
• physical stress (illness, surgery, infection, etc.) or psychological stress (mourning a death, new job, moving, etc.)
• taking certain drugs (e.g.: cortisone)

Hyperglycemia can also be caused by two lesser known phenomena: the dawn phenomenon and the Somogyi effect.

Preventing hyperglycemia

In most cases, hyperglycemia can be avoided by taking the following precautions:

• Measure your blood glucose (sugar) levels regularly.
• Follow a daily meal plan designed by a dietitian.
• Take your insulin or antidiabetic medication as prescribed.
• Adjust your insulin dose based on your medical prescription

Treatment

If you experience hyperglycemic symptoms, you should:

• take your blood glucose (sugar) readings frequently
• if you have type 1 diabetes: if your blood glucose level is higher than 14 mmol/L, check for ketones in your urine or blood
• drink lots of water to prevent dehydration (250 ml of water every hour)
• adjust your insulin as medically prescribed
• identify the cause of the hyperglycemia and take appropriate measures, if possible

Emergency situations

Call a doctor or get to Emergency if:

• your blood glucose reading is higher than 14 mmol/L with ketones
  • in your urine: a “medium” to “high” level
  • in your blood: a level higher than 1.5 mmol/L
• if you have type 1 diabetes: your blood glucose level is higher than 20 mmol/L with nausea, vomiting and/or abdominal pain
• if you have type 2 diabetes: your blood glucose level is higher than 25 mmol/L with excessive drowsiness
• you cannot retain liquids due to vomiting or diarrhea
• your state of consciousness changes: confusion, agitation, lack of reaction to stimulation, hallucinations or unusual behaviour
• you exhibit signs of dehydration: dry mouth, sunken eyes, dry skin, etc.
• your body temperature has stayed above 38.5 °C for more than 48 hours.

These symptoms could signal a hyperglycemic emergency.

Research and text: Diabetes Québec Team of Health Care Professionals

July 2014

References:

Geoffroy L., and Gonthier, M., (2012) “L’hyperglycemia et l’acidose diabétique,” Le diabète chez l’enfant et l’adolescent, 2nd edition,. Montréal: Éditions du CHU Ste-Justine, pp. 355-364.

S.A. Imran et al., (2013) “Targets for Glycemic Control,” Canadian Diabetes Association 2013 Clinical Practice Guidelines for the Prevention and Treatment of Diabetes in Canada, (Canadian Journal of Diabetes, vol. 37, pp. S31-S34), Canadian Diabetes Association.

CHUM-Hotel-Dieu Metabolic Medicine Day-care Centre (2013), “Hyperglycemia”, Understand Your Diabetes and Live a Healty Life, Montreal: Rogers Publishing Limited, pp. 16-19.

Info-Santé (811 hot line) protocol for hyperglycemia (2011).