What Blood Tests Require Fasting?

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Metabolic profiles often require fasting, according to Adams Memorial Hospital. Other fasting blood tests include glucose testing, the renal function panel, and the lipid profile. When fasting for these tests, patients are not to eat or drink during the 12 hours before the test.

Metabolic profiles are groups of blood tests performed from a single sample of blood. The comprehensive metabolic profile provides information concerning cholesterol, glucose, proteins, functioning of the liver and kidneys, and electrolytes, according to MedlinePlus. They provide an overall snapshot of how the body is functioning.

Doctors use a fasting blood sugar test as a screen for diabetes, according to WebMD. Normally, the body regulates the glucose level by producing insulin; however, diabetics do not produce insulin, or their bodies do not use it effectively. If the blood glucose levels remain elevated over time, they cause damage to the nerves, eyes, kidneys and other tissues.

The renal function panel includes tests that determine how well the kidneys are functioning, according to the National Kidney Foundation. These tests show how quickly the body is able to filter waste from the blood and if proteins are leaking through the kidneys.

The lipid panel is a cholesterol test, according to WebMD. It tests for good and bad cholesterol. It also returns the triglyceride level and overall cholesterol levels.