Why Fasting is Required for Some Blood Tests

Have you ever wondered why your doctor ordered you to fast before you have blood drawn for further testing?  Fasting is not easy, as it requires you to avoid eating for a long period of time.  This can cause issues, like fatigue, hunger, and lightheadedness.  When you need to have blood drawn for further testing that is sent to labs specializing in dermatopathology in Pittsburgh, PA, you will want to follow doctor's orders as best as possible to avoid discrepancies in test results.  There are a few reasons why fasting is required for some blood tests that are sent to labs.

Blood Glucose Tests

Fasting glucose tests can determine and diagnose diabetes, which indicates that there is an issue with blood sugar levels in the body.   It is important for patients to avoid eating or drinking anything for 8 to 10 hours before having blood drawn to ensure that an accurate blood glucose level is being recorded.  This is essential in ruling out or diagnosing the possibility of diabetes.

Blood Cholesterol Tests

Having a high level of cholesterol can put you at risk for many other health conditions, which can have devastating effects on your health.  Blood cholesterol tests are used to indicate the levels of fats in the blood, which will naturally fluctuate once you have eaten certain foods.  Fasting for 9 to 12 hours before having blood drawn is important to give an accurate depiction of the levels of fats normally stored in your blood.

Iron Blood Tests

Blood that is drawn to test the levels of iron also require fasting.  These tests are done to determine whether you have a deficiency of iron in your blood, resulting in anemia.  Iron is absorbed very quickly from foods into the blood, so fasting for the morning before the test is essential in providing accurate results.  Also, those who take supplements should also refrain from taking those supplements for at least 24 hours before having their blood drawn.

Comprehensive Metabolic Tests

These tests are done in order to determine diseases or disorders related to the kidneys, blood sugar, and electrolyte balance.  When you have these tests completed, you will want to fast for at least 10-12 hours before having your blood drawn to provide accurate results that are tainted by eating particular foods first.

These are just a few of the main reasons why fasting is required to have some blood drawn for further lab testing.  At our lab facility that specializes in dermatopathology in Pittsburgh, PA, we perform many tests that can determine specific diagnoses and then pinpoint the right course of treatment.  Our patients that adhere to the suggestions of their doctor typically don't need to have multiple courses of the same test.  If you want to hear more about our lab testing services, contact us to hear more today.