Glucose is a simple sugar that is utilized throughout the body for energy. Excess glucose is converted to fat and stored away. When the body has insufficient glucose, it will break down and convert fat and protein into glucose to supply all the cells in the body. Glucose is transported through the bloodstream. In high quantities it can be toxic to the body’s cells. Therefore the body has a mechanism to regulate the blood glucose levels – ensuring that it is not excessively high to cause tissue damage, but not too low to be insufficient for the energy needs of all cells.
What is hyperglycemia?
Hyperglycemia is abnormally high blood sugar (glucose) levels. It is one of the main symptoms of diabetes mellitus. However, hyperglycemia and diabetes mellitus are two different conditions. In diabetes mellitus, the hormonal mechanisms that regulate the blood glucose levels within a normal range are defective. Therefore, the blood glucose levels rise above the normal limit. Hyperglycemia can occur in many different situations and not only in diabetes mellitus. However, the prevalence of diabetes mellitus across the globe, and particularly in the elderly, means that hypergycemia in seniors is most likely a consequence of diabetes.
Blood Glucose Levels
Various hormonal mechanisms in the body maintain the glucose concentration in the blood within a narrow range of 80-110 mg/dL (milligrams per deciliter). After a meal, the blood glucose level may rise temporarily to a value as high as 180 mg/dL (also called post-prandial blood glucose level). However, hormonal mechanisms subsequently bring this elevated blood glucose value back within the normal range.
Hyperglycemia is defined as blood glucose levels above 200 mg/dL. However, the accepted range of normal and abnormal blood glucose values vary slightly. In most cases, a fasting blood glucose level above 130mg/dL and a post-meal blood glucose level above 180 mg/dL are considered indicative of hyperglycemia.
In mild cases, hyperglycemia may not produce any symptoms or mild symptoms that are often ignored. The symptoms of hyperglycemia may not become evident till the blood glucose level reaches 250-300 mg/dl. High blood sugar can have widespread effects on various organ systems in the body, especially if left untreated for a long time. Some of the symptoms of hypergycemia, which are therefore also characteristic symptoms of diabetes mellitus, includes :
- Dryness of the mouth
- Excessive thirst (polydipsia) and dehydration
- Increased frequency of urination (polyuria) and glucose in urine
- Increased frequency of feeling hungry (polyphagia)
- Blurred vision
- Fatigue and drowsiness
- Weight loss
- Seizures and coma (in severe hyperglycemia)
Untreated hyperglycemia can cause the following serious complications over the long term:
- Damage to nerves
- Damage to blood vessels
- Damage to kidneys
- Wounds and infections of the legs and feet usually as a consequence of nerve and blood vessel damage
- Disturbance of vision
- Ketoacidosis – increased levels of ketones in the blood and urine leading to drop in the blood pH which can progress to coma.
- Problems with gastrointestinal tract leading to diarrhea or constipation
Causes of High Blood Glucose
- The hormone, insulin, regulates blood glucose levels by stimulating various tissues to take up glucose from the blood. In this way it clears the blood of excess glucose. A deficiency or resistance of the body’s cell to insulin (like in diabetes mellitus) is one the main reasons for hyperglycemia.
- Certain drugs may produce hyperglycemia (either acute or chronic). Some examples of these hyperglycemia inducing drugs include corticosteroids, beta blockers, thiazide diuretics, niacin, protease inhibitors, amphetamine, olanzapine, duloxetine.
- Other than diabetes, conditions such as acute stress, myocardial infarction (heart attack), stroke, pancreatic diseases, brain tumors and hormonal dysfunctions of adrenal, pituitary, and thyroid glands could also cause hyper-glycemia.
Treatment of Hyperglycemia
Hyperglycemia should be treated promptly because prolonged high blood sugar levels can damage many organs systems and support infections. The treatment of hyperglycemia is aimed at treating the underlying cause. In diabetics, insulin injections are given to control blood glucose levels. Regular exercise can help in normalizing blood glucose levels. However, exercise should be avoided if the patient has ketoacidosis along with hyperglycemia. Changes in diet are essential to limit the intake of sugar in hyperglycemia and diabetes. If the cause of hyperglycemia is the intake of certain drugs, then those prescriptions much be changed immediately. Other diseases that could cause hyperglycemia should be treated promptly.
Last Updated: July 14th, 2012 by