High blood sugar (Hyperglycemia)

Hyperglycemia is a term referring to high blood glucose levels – the condition that often leads to a diagnosis of diabetes.

High blood glucose levels are the defining feature of diabetes, but once the disease is diagnosed, hyperglycemia is a signal of poor control over the condition.

Hyperglycemia is defined by certain high levels of blood glucose:1

Fasting levels greater than 7.0 mmol/L (126 mg/dL)

Two-hours postprandial (after a meal) levels greater than 11.0 mmol/L (200 mg/dL).

Chronic hyperglycemia usually leads to the development of diabetic complications.2

Typical signs and symptoms of hyperglycemia include:

Prevention of hyperglycemia for people with a diabetes diagnosis is a matter of good self-monitoring and management of blood glucose levels, including adherence to insulin regimes if necessary.

For someone who has not been diagnosed with diabetes, symptoms of hyperglycemia need to be reported to a doctor so that they can test for diabetes – other conditions can also lead to hyperglycemia.

Control of high blood sugar is important to prevent complications caused by chronic hyperglycemia. A doctor may need to review the treatment plan for a diabetes patient who becomes hyperglycemic and they may decide to take one of the following actions:

Raise the insulin dose
Recommend dietary changes
Recommend more exercise
Recommend closer glucose monitoring

It is important to attend to hyperglycemia since it can lead to a dangerous complication known as ketoacidosis.

High levels of glucose in the blood mean that insufficient levels of glucose are available to cells for their energy needs. As a result, the body resorts to breaking down fat so that energy is derived from fatty acids. This breakdown produces ketones, leading to higher acidity of the blood.

Diabetic ketoacidosis requires urgent medical attention and, alongside hyperglycemia and its symptoms, is signaled by: