Hyperglycemia, also known as high blood sugar, is a side effect and clinical symptom of diabetes. In a normal person, blood sugar levels are maintained by the action of the hormone insulin, which acts to convert glucose in the blood into energy for use by the cells. Hyperglycemia occurs when the body either does not produce insulin, or the insulin produced cannot be utilized. In uncontrolled diabetes, incidents of hyperglycemia can lead to both short term and long term complications.
Cardiovascular Complications
Individuals with chronic hyperglycemia caused by uncontrolled diabetes may develop problems within the circulatory system. Heart attacks and stroke become more likely in these individuals. Poor circulation also becomes an issue in individuals with chronic hyperglycemia, including a loss of proper circulation to the legs and feet, which can lead to skin problems and infections.
Eye Problems
Hyperglycemia often leads to problems with the eyes and vision. Cataracts, a clouding of the lens of the eye, and glaucoma may develop. Diabetic retinopathy is a serious condition in which hyperglycemia causes damage to the blood vessels supplying the retina of the eye. Diabetic retinopathy can cause complete blindness.
Nerve and Brain Problems
Hyperglycemia can also damage nerve cells. In the long term, this can cause permanent nerve damage called neuropathy. Someone with neuropathy may experience pain or tingling sensations in the extremities as a result of this damage. In the short term, temporary problems in the brain can occur if blood sugar reaches over 270 mg/dL, causing a decrease in mental abilities, including mathematics and verbal skills, according to a 2001 University of Virginia study.
Kidney Problems
Nephropathy, severe kidney damage, can occur as the kidneys attempt to remove excess glucose from the blood. In extreme cases, this can result in complete kidney failure.
Diabetic Ketoacidosis
Diabetic ketoacidosis, also known as DKA or diabetic coma, occurs when blood sugar levels rise for prolonged periods of time and insulin production stops completely. The body begins to break down fats, which produces toxic ketones. Ketones accumulate in the blood, spill into the urine and can lead to coma or death. Since diabetic ketoacidosis can progress rapidly to coma and death, it is considered an emergency condition and needs to be treated at a hospital.
Diabetic Hyperosmolar Syndrome
Someone with hyperglycemia may develop diabetic hyperosmolar syndrome if the blood glucose cannot be cleared from the system because of faulty insulin. The excess glucose builds up to dangerous levels and the body begins to dump it into the urine, causing excessive urination. This can rapidly lead to life-threatening dehydration.
