Do I need to fast for venous blood drawing?

Blood test is a necessary medical diagnostic technology. It is very important in modern life. This technology has a very high diagnostic effect and uses scientific principles to accurately analyze the internal health status of the body. Blood drawing generally focuses on venous blood drawing, because venous blood is the main carrier of metabolism. Let’s take a look at whether fasting is required for venous blood drawing? I hope everyone can understand it.

Generally speaking, most of the tests that require fasting blood draw are biochemical tests. For example, liver function, sugar, protein, lipids, and various inorganic ions (potassium, sodium, calcium, phosphorus, etc.).

The biochemical test mentioned above is a method of measuring the biochemical components of blood using quantitative analysis methods to understand their trace changes and make a diagnosis based on them.

The normal values ​​of biochemical tests are obtained by measuring the fasting blood of normal people and processing them using statistical methods. Therefore, each test result has a normal range.

Which items require fasting blood test?

1. Liver function: Alanine aminotransferase, aspartate aminotransferase, total bile acid and glutamyl transpeptidase, which reflect liver metabolism, and total protein, albumin and globulin, which reflect protein metabolism, are greatly affected by diet and require fasting.

2. Renal function (including uric acid): Urea nitrogen, creatinine and uric acid are greatly affected by diet and exercise, and require fasting.

3. Blood biochemistry: including electrolytes, etc. Eating will affect the results, so you need to be on an empty stomach.

4. Blood sugar (fasting) and glycosylated serum protein: The former refers to the blood sugar level measured between 6 and 10 in the morning, when the patient is fasting for 8 to 14 hours from after dinner the day before to the next morning. "Super fasting" blood sugar after 10 in the morning will affect the test results. Glycated serum protein can reflect the average blood sugar level in the past 4 weeks. The result is positively correlated with blood sugar concentration and requires fasting blood.

5. Blood lipids: There are many factors that affect the results of blood lipid tests, among which food has the greatest influence. After eating, especially after a heavy meal, the fat in the food passes through the small intestine and enters the blood, causing a significant increase in triglyceride levels.

6. Blood rheology measurement: It is necessary to measure the formed elements such as sugar, fat, protein, urea nitrogen, creatinine and blood cells in the plasma. Fasting blood must be drawn and anticoagulated in a quiet state.

7. Immunoglobulin and rheumatism items: In order to prevent the influence of serum samples, blood drawing on an empty stomach is also required.

8. Sex hormones: The best time to draw blood is on the 2nd to 3rd day of the menstrual period (for prolactin items, you need to sit still for 20 minutes before drawing blood), and the blood must be drawn on an empty stomach.