High blood glucose levels, medically referred to as hyperglycemia, is a condition marked by abnormally high levels of sugar in the blood. Glucose levels in your blood accumulate when your body does not have enough insulin or when your body cannot use insulin properly.
Causes of Hyperglycemia
Hyperglycemia most commonly occurs as a complications of diabetes, but can occur as a result of renal failure, inflammation of the pancreas, hyperthyroidism, excessive food intake or the stress that occurs in response to trauma, heart attack or stroke.
Normal Values
Blood glucose levels are tested with a variety of different lab tests. A fasting glucose test evaluates glucose levels after a prolonged period without food. Normal blood glucose levels are defined as 70 to 99 mg/dL.
An oral glucose tolerance test is another type of glucose test that measures your body's reaction to glucose. During an oral glucose tolerance test, you will consume a drink that contains 75 mg of glucose. Two hours after you consume the drink, your glucose levels are tested. If you can tolerate glucose normally, your glucose levels will measure less than 140 mg/dL.
Abnormal values on either of these glucose tests are indicative of high blood glucose levels and can mean that you have an underlying condition that affects the way your body uses glucose.
Complications
Untreated hyperglycemia can lead to a variety of different chronic complications. Some of the most common long-term complications include nerve damage, heart disease, kidney damage, cataracts, tooth infections, gum infections, joint problems, osteoporosis, decreased blood flow, foot problems and diabetic retinopathy, which is damage to the blood vessels in the eye.
Emergency Situations
Extremely high blood glucose levels can lead to dangerous, potentially life-threatening complications. Diabetic ketoacidosis is one of the most common of these complications. Diabetic ketoacidosis occurs when your body begins to break down fat for energy because it cannot utilize glucose properly. The breakdown of fat produces toxic compounds called ketones. If ketones accumulate in your bloodstream, it can lead to coma or death.
Another dangerous complication is called diabetic hyperosmolar syndrome. This condition occurs when your body produces insulin but cannot use it properly. As a result, your body cannot gain access to the energy from carbohydrates or fat. Instead, glucose is deposited into your urine, where it triggers an increased need to urinate. This constant urination can lead to dehydration and eventually cause a coma.
