Hyperglycemia is abnormally high blood sugar. This article discusses hyperglycemia in infants.

A healthy baby's body usually has very careful control of blood glucose levels. Insulin is the main hormone in the body that regulates glucose. Sick babies may have poor insulin function or low amounts, which causes poor control of the blood sugar.

There can be specific causes of ineffective or low insulin, such as infection, liver problems, hormone problems, and some medications. Rarely, babies may actually have diabetes, with low insulin levels that result in high blood sugars.

Babies with hyperglycemia often have no symptoms.

Sometimes, babies with high blood sugars will produce large amounts of urine and become dehydrated. High blood sugars may be a sign that the baby has added stress on the body due to problems such as an infection or heart failure.

A blood test to check glucose (blood sugar) levels can be done at the bedside or in a laboratory.

There are usually no long-term effects from high blood sugar unless the baby has diabetes.