What is a High Blood Sugar Level Range?


According to the American Diabetes Association (ADA), there are nearly 18 million diabetics in the United States, with nearly 25 percent of them unaware that they have the disease. Diabetes is a serious metabolic disorder that is caused by the pancreas not making enough insulin, or the body's resistance to it. Insulin is a hormone that helps the body assimilate blood glucose to produce energy. When there is a problem metabolizing blood glucose, its concentrations rise in the blood—a condition called hyperglycemia or high blood sugar.

The Ups and Downs of Blood Sugar

Everyone experiences moderate fluctuations in their blood sugar levels. The normal blood glucose range in healthy individuals is between 70 and 125 mg/dl. During times of prolonged physical activity, the glucose level can dip below 50 mg/dl. After carbohydrate-rich meals, it can soar to over 180. That's normal, according to Dr. Edward Horton of the Joslin Diabetes Center. However, when blood sugar levels remain low or high, symptoms start to appear.

Causes of High Blood Sugar

The most common cause of high blood sugar is diabetes. There are two types—Type I and Type II. Type I diabetes is called insulin dependent because there is not enough natural insulin produced by the pancreas, so the diabetic is dependent on insulin injections. Type I diabetics often get the disease very early in life, hence its alternate name of juvenile diabetes. Type II is called insulin independent (also called adult onset diabetes) because the body may not produce enough insulin, or body tissues may be resistant to insulin and so it is perceived as a shortage, according to the Mayo Clinic. Type II diabetes is called adult onset diabetes because it typically affects adults later in life. It accounts for over 90 percent of diabetics, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

The Long Term Effects of Hyperglycemia

Regardless of which type of diabetes one has, the results are the same. Hyperglycemia, or abnormally high concentrations of blood sugar for extended periods of time, are first detected after the sufferer experiences such symptoms as unusual thirst, constant urination and hunger, profuse sweating, dizziness and a general sense of disorientation or malaise, NIDDK reports. Inside the body, high concentrations of blood sugar can begin damaging sensitive tissues and organs and can ultimately cause a complete failure of systems, according to NIDDK. Hyperglycemia accelerates coronary artery disease, causes kidney failure and, if left uncontrolled, can lead to loss of vision, nerve damage and amputation of limbs.

Diagnosing High Blood Sugar

The easiest way to detect high blood sugar is by having your blood drawn as part of your annual physical examination. Part of what they're measuring is your fasting blood glucose level. It's important that the test be done while fasting, the American Diabetes Association says, because it's a good indicator of your normal level of glucose without the influence of exercise or food. The normal range for fasting blood glucose is 70 to 125 mg/dl. If your values are higher than 130 mg/dl, your doctor may ask you to repeat the test in a week. If your results are high during the second test, an oral glucose tolerance test (OGTT) will likely be ordered. During an OGTT, the patient is asked to drink a high concentration of glucose in liquid. Blood samples are drawn in the beginning and at 2-hour intervals throughout the day to determine how well the body processes glucose. If the glucose concentrations remain high, you may have diabetes. Another way to test for hyperglycemia is to measure your hemoglobin A1c (HbA1c). Blood glucose competes with oxygen by attaching itself to the hemoglobin in the red blood cells, according to the Mayo Clinic. High concentrations of HbA1c can interfere with the way that cells get oxygen from the blood. While standard blood glucose tests measure the amount of glucose in your blood at that time, HbA1c represents the average amount of glucose in your blood over the entire lifespan of your red blood cells—about 120 days. Normal HbA1c concentrations should be less than 7 percent of your total hemoglobin, the Mayo Clinic Advises.

Dealing with High Blood Sugar

If you suspect that you have high blood sugar, visit your doctor right away. You may have had hyperglycemia or diabetes for a long time—maybe years. As a result, it likely has already caused significant damage to your body, the ADA warns. The good news is that there are a number of effective ways to treat high blood sugar, including medication, diet and insulin injections. They include changes in your diet, exercise and medications.