These tests typically require fasting: Fasting blood glucose measures the amount of glucose ( sugar ) in your blood to test for diabetes or prediabetes . Typical fasting time: At least 8 hours
What types of blood tests require fasting? Glucose testing that checks blood-sugar levels and tests that determine your cholesterol, triglycerides, and high-density lipoprotein (HDL) levels usually require fasting. Other lab tests may require fasting, which is why you should ask your doctor.
Numerous blood tests require fasting for up to 12 hours before the test, including lipid profile, renal function panel, glucose level, chem 7, basic metabolic profile, comprehensive metabolic profile and vitamin B-12, says Adams Memorial Hospital. Other fasting tests include tests for iron levels and liver function.
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.
However, fasting is required before commonly ordered tests for glucose (blood sugar) and triglycerides (part of the cholesterol, or lipid, panel) for accurate results. To continue reading this article, you must login .
Most fasting lab tests require 8, 12 or 14 hours of fasting. If you are not certain how long you are supposed to fast, call your doctor's office or the lab to ask. If you take your tests and have not fasted the proper amount of time you might have to repeat the tests.
Administering a lab test may have ample of instructions to be followed. One such is fasting before sample collection. There are a couple of diagnostic tests that require fasting.
Lab tests that require fasting (nothing but water after the evening meal on the day before your test): cholesterol . HDL cholesterol . triglycerides . lipid panel . fasting glucose . growth hormone . vitamin B12 . folate . glucose tolerance test . Lab tests to be drawn before 9:00 AM: testosterone . AM cortisol . pituitary function tests
Some blood tests will require you to fast beforehand. In these cases, your doctor will instruct you not to eat or drink anything, except water, in the hours leading up to the test.
Examples of some common laboratory tests that require advance preparation include: Glucose tolerance, fasting, and two-hour post-prandial blood glucose tests: fasting or eating meals at specific times may be required. Li pids profile (triglycerides, cholesterol, etc.): fasting for 9-12 hours may be required.