Glucose - Urine

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Why is the Test Performed?

This test is most commonly used as a screening test for possible diabetes mellitus or to monitor control of blood glucose in diabetes.

Most dietary carbohydrates eventually end up as glucose in the blood. Excess glucose is converted to glycogen for storage by the liver and skeletal muscles after meals. Glycogen is gradually broken down to glucose, and it is then released into the blood by the liver between meals.

Glucose is a major source of energy for most cells of the body. Some cells (for example, brain and red blood cells), are almost totally dependent on blood glucose as a source of energy.

The brain, in fact, requires that glucose concentrations in the blood remain within a certain range in order to function normally. Concentrations less than about 30 milligrams per deciliter (mg/dl) can produce confusion or unconsciousness. High glucose concentrations (greater than 300 mg/dl) may cause similar symptoms if associated with dehydration, infection, or acidosis.

The major hormone regulating glucose concentration in the body is insulin (although other hormones such as glucagon, epinephrine, and cortisol, also affect it). Glucose levels are measured most commonly to diagnose diabetes, or to monitor adequacy of diabetic control.

Diabetes is a very common disease -- affecting about 2% of the general population. Diabetes results from deficient insulin or sensitivity to insulin. Type I diabetics require daily injections of insulin. Injection of too much or too little insulin can be dangerous.