Why do I have to go fasting? Can I drink water before a blood draw?

Fasting blood refers to the venous blood taken in the early morning before eating, because the various biochemical components of the fasting blood drawn at this time are more stable and more objective. Generally speaking, most of the fasting blood tests that require fasting blood tests are biochemical test items, which are easily affected by dietary factors, so in order to avoid differences caused by dietary factors, the normal value range of these test items is obtained by statistical processing based on the fasting blood test of normal people, such as glutamate propylene and aspartate aminotransferase in liver function tests, and the range of normal people is zero to 40 units per liter. The biggest advantage of fasting blood test is that it can avoid the influence of dietary factors, make the test results more objective, and can more truly reflect the biochemical changes of the body.

If blood is collected after eating, there will be temporary changes in the biochemical components in the blood, and the measured results will not objectively reflect the real situation of the body, which will affect the accuracy of clinical judgment.

If you eat before the morning blood test, after the food is digested, a large number of chylomicrons will be quickly inhaled into the blood, at this time the blood will also be turbid, medically called fat blood, if the blood appears turbid due to chylomicrons, then it is difficult for the inspector to observe clearly, especially when the fat plasma is determined by polylipidemia, it affects the accuracy of the measurement, so in order to make some blood test items more accurate, it is hoped that patients must follow the doctor's instructions.

Under normal circumstances, you can't drink water before drawing blood, so you should try to avoid drinking water, because drinking water will have a diluting effect on the blood, which is likely to affect some results of blood tests, so it may cause some blood sugar test results.

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This is because the level of blood tests is most accurate when taken on an empty stomach, and it will not be affected by the external environment, and there will be no serious changes in factors such as red blood cells and white blood cells in the body. You can't drink water before the blood draw, but you can replace food and water in time after the blood draw.

Because fasting can be detected more accurately, it avoids the impact on various detection indicators, avoids errors, and the functions of the body are relatively perfect at this time; I don't think you should drink water before your blood is drawn.

Because if you eat something, it may interfere with the result; It is possible to drink a small amount of water before the blood draw, within 100 ml.

Drinking water is no longer considered fasting, so you must not drink water when taking blood, so the test is not accurate.

Of course yes, as long as you don't eat. But you don't drink drinks or anything, just drink a little plain water.

Of course, after drinking water, it is not considered an empty stomach, so do not drink water or eat, otherwise you will not be able to draw blood at all, and you will waste your time.

Question 1: Can I drink water during fasting examination Generally speaking, I can't drink water during fasting physical examination.

The requirement for fasting is to abstain from food and water for 10 to 12 hours, and avoid the effects that eating may have on the results of the physical examination.

If you feel very thirsty, you can also drink a small amount of water to ensure the normal water of the body**, but not too much, so as not to dilute the blood and affect the results of the physical examination. In addition, if there is a chronic disease that requires long-term**, you should ensure that you take the medicine normally, without interruption, and you can take it with a small amount of water.

There are other things to pay attention to in the physical examination

1. Three days before the physical examination, you should not participate in the dinner, too sweet, too salty, too greasy food should be avoided, no alcohol, try to eat vegetarian. Fasting is generally required after 8 o'clock in the evening, and early bedtime is required.

2. On the day of the physical examination, skip breakfast, and take physical examination items such as blood pumping and abdominal ultrasound examination on an empty stomach. The medical examination center arranges breakfast for medical examination.

3. When performing **B ultrasound for women and B ultrasound for men, you need to hold urine.

4. Women need to urinate when they have a ** examination.

5. Women should not do ** examination and laboratory urine examination during menstruation; Pregnant women should not have x-rays.

6. After venous blood drawing, press the puncture point of the needle with a cotton ball for two minutes, and do not rub it to prevent the formation of hematoma.

7. When undergoing physical examination, you should be naturally relaxed, have a peaceful mind, and provide the doctor with real medical records and your own physical condition or feelings.

8. When the examination results indicate that there is an "abnormality", do not shy away from the disease, consult the doctor in time, and conduct a review or ** according to the doctor's advice.

9. Insist on completing the prescribed physical examination items to avoid missing the diagnosis.

Question 2: Can I drink water on an "empty stomach" before the blood test in the morning Hello, do not drink water before the blood test, because drinking water will dilute the blood, and the test results will be biased. Some people's blood viscosity is related to his sharp physique, or it may be related to the composition of blood cells in his body, just like it is difficult to stop bleeding after someone bleeds.

Question 3: Can I drink water before a fasting blood test Hello, before doing a blood test, it is best to have an empty stomach. Not drinking water or eating is more beneficial to the examination, so as not to affect the examination because of the diet.

Question 4: Can I drink water in the morning on an empty stomach Blood draw, can I drink water in the morning on an empty stomach.

Question 5: Can I drink water in the middle of the night for a blood test on an empty stomach in the morning towards evening, just before it got dark

Question 6: Can I drink water in the morning for an empty blood test On the theory of not drinking water before blood drawing, but some people will be thirsty in the morning after a night of rest, and it is no problem to drink a little boiled water at this time, but the amount should not be too much, 200ml is more appropriate. Because the blood is very viscous after people wake up in the morning, drinking a small amount of water can have a diluting effect on the blood.