Many people are curious about whether or not they need to fast before undergoing certain blood tests. The answer is, it depends on what type of blood work is being done. Here are some of the most common blood tests that require fasting:.

Lipid Panel

A lipid panel is a blood test that measures your total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. This test is typically done to evaluate your risk for heart disease.

Fasting for 9-12 hours is necessary, as eating can cause your triglyceride levels to temporarily rise, which can affect the accuracy of the test.

Blood Glucose Test

The blood glucose test measures the amount of sugar (glucose) in your blood. This test is often done to diagnose diabetes or to monitor glucose levels in people who have already been diagnosed with the disease.

Fasting for 8-12 hours is necessary for accurate results because your blood glucose levels can be temporarily elevated after eating.

Basic or Comprehensive Metabolic Panel

A basic or comprehensive metabolic panel is a group of blood tests that provide information about your body’s metabolism. These tests include measurements of electrolytes, kidney function, liver function, and blood glucose levels.

Fasting for 8-12 hours is necessary for accurate results because eating can affect the levels of some of these substances in your blood.

Iron Test

The iron test measures the amount of iron in your blood. This test is often done to diagnose or monitor iron-deficiency anemia. Fasting for 12 hours is necessary because recent meals can affect the results of this test.

Gamma-Glutamyl Transferase (GGT)

The GGT test measures the level of GGT in your blood. This test is typically done to evaluate liver function or to monitor liver disease. Fasting for 8-12 hours is necessary because recent meals can affect the results of this test.

Cortisol Test

The cortisol test measures the level of cortisol in your blood. This test is often done to diagnose or monitor conditions such as Cushing’s syndrome or Addison’s disease.

Fasting for 12 hours is necessary because recent meals can affect cortisol levels.

Ferritin Test

The ferritin test measures the level of ferritin in your blood. Ferritin is a protein that stores iron in your body. This test is often done to diagnose or monitor iron-deficiency anemia.

Fasting for 12 hours is necessary because recent meals can affect the results of this test.

Insulin Test

The insulin test measures the level of insulin in your blood. This test is often done to diagnose or monitor conditions such as diabetes or hypoglycemia. Fasting for 8-12 hours is necessary because eating can affect the accuracy of the test.

Parathyroid Hormone (PTH) Test

The PTH test measures the level of parathyroid hormone in your blood. This test is often done to diagnose or monitor conditions such as hyperparathyroidism. Fasting for 9-12 hours is necessary because eating can affect the accuracy of the test.

Triglycerides Test

The triglycerides test measures the level of triglycerides in your blood. This test is often done as part of a lipid panel to evaluate your risk for heart disease.

Fasting for 9-12 hours is necessary, as eating can cause your triglyceride levels to temporarily rise, which can affect the accuracy of the test.

It’s important to follow your doctor’s instructions about fasting before any blood tests. If you’re unsure about whether or not you need to fast for a particular test, be sure to ask your doctor.