PT Health Life – Whether a blood test requires fasting or not depends on the type of test the doctor prescribes. Below are the instructions to fast before taking the test.
1. Tests require fasting from breakfast
Not all blood tests require fasting beforehand. However, for nearly all blood tests , doctors require fasting. Because fasting is a huge deciding factor in the accuracy of blood test results. Because vitamins , minerals, fats, carbohydrates, proteins, etc. contained in all foods and drinks can affect blood level measurements, clouding test results.
In these cases, your doctor will instruct you not to eat or drink anything, except water, for several hours before the blood test. And usually blood sampling is done in the morning.
Blood tests that require fasting include:
– Fasting blood sugar test: This test is intended to diagnose diabetes and gestational diabetes. To do this test, you need to fast for at least 8 hours.
– Iron test: Please do not eat anything the morning before the test. If you are taking iron tablets or multivitamin supplements containing iron, you should stop using them 24 hours before the test.
– Blood fat test: Blood fat can increase after eating. Therefore, this is the type of test where you need to fast for about 8 to 10 hours before the test.
– Kidney function assessment test : Fast for 8 – 10 hours before the test.
– Test when doing Helicobacter pylori C13 test in the stomach : Do not eat or drink 2 hours before; Do not use antibiotics before 4 weeks (including Bismuth compounds); Do not take medication related to treatment 1 week before the test. If you do, please discuss it with your doctor.
2. Some notes before blood test
Before taking blood, you need to rest, do not overexert yourself, have strong emotions… because the glucose concentration in the blood can increase because the body needs more energy at that time, so it pushes more glucose into the blood. Therefore, before taking a blood test, you should rest for 10 minutes before taking blood for testing. You should avoid doing heavy work and avoid making your body tired.
Do not use stimulants 24 hours before the test: Beer, wine or alcoholic beverages increase liver enzymes, affecting blood test results.
Do not drink coffee or smoke before a blood test. Drinking coffee or other caffeinated beverages such as energy drinks or colas within 1 hour before a blood test may cause some of your blood test results to be higher than normal. .
Smoking cigarettes or using any medications, even over-the-counter nasal drops, before a blood test can produce inaccurate results.
In addition, you should also avoid sweets and fatty foods and avoid eating too much before the test day because all of these things can affect the triglyceride test results.
You may drink water before your blood test, unless otherwise directed by your doctor. Cooled boiled water or bottled water are fine, but do not squeeze lemon into the water. Do not drink carbonated, flavored or other drinks, including tea. Water makes the veins more tense and easier to see when taking blood for testing.
Summary: Fasting before blood tests for some diseases is very important. The length of fasting required varies depending on the specific test.
For most tests, you are asked not to eat or drink anything other than water for 8 hours before the test.
For some tests, fasting for 12 hours may be required.
Therefore, when going for a health check-up, consult your doctor to learn the rules for effective testing.
