Why do I have to have an empty stomach when I have a blood test? Does eating breakfast have an impac

When fasting, the body is in a relatively basal metabolic state, which can exclude the influence of factors such as diet, and the test results are more accurate; Eating breakfast will have a certain impact on the data, because after eating, the body's liver, kidneys, blood lipids and blood sugar will undergo certain changes.

This is because the blood drawn on an empty stomach does not affect the final value; If you eat breakfast, it will have an impact on the data, which will lead to inaccurate data.

Because if you eat, the data is inaccurate; Eating breakfast has a very big impact on the data, so doctors usually ask you to have blood drawn in the morning when you don't eat breakfast.

Causes abnormalities in blood test results.

For example, eating foods high in fat can significantly increase triglycerides several times; Consuming foods high in sugar can cause a rapid rise in blood sugar within two hours. These can affect the composition of the blood, causing a "misjudgment".

After eating in the evening of the first day to the early morning of the next day, the fasting time is more than 10 hours, and various substances in the body have reached relative stability and balance, and the food factors have basically no effect on the blood composition, and the blood draw can get relatively stable and accurate results at this time.

Therefore, try to exercise as much as possible before blood drawing, do not eat food, keep an empty stomach, drink a small amount of water, and take it on time except for certain medications. Failure to do so will interfere with the results of some experiments.

Generally speaking, most of the laboratory tests that require fasting blood are biochemical tests, such as liver function, blood sugar, protein, lipids, and electrolytes potassium, sodium, chloride, etc. The reference values of biochemical tests are obtained by statistical processing based on the fasting blood of healthy individuals. This is because the venous blood taken before meals in the early morning of the same day has relatively stable biochemical components, and the measured values can reflect the biochemical changes of the body more realistically.

If blood is collected after eating, the biochemical components in the blood (such as blood glucose, blood lipids, etc.) will change temporarily, and the measured results cannot reflect the real condition of the body, and cannot be compared with the reference value measured in fasting blood, so it is impossible to make accurate clinical judgments. After meals, blood sugar and blood lipids will increase, which will affect the accuracy of the results. The aminotransferases of normal people rise, and the judgment of "abnormal" is obtained; The number of people with abnormal aminotransferases is even higher.

Although it is said to be fasting, there is no need to abstain from water, and a small amount of water drinking generally does not have a significant effect on the test. However, drinking large amounts of water should be avoided as this can cause blood thinning. Affects the results of tests such as blood counts, making them lower than true.

You can't drink drinks, because most drinks contain sugar, and drinking blood will raise blood sugar levels.

Is there also the best time to draw blood on an empty stomach? Don't ignore the two precautions before the physical examination, so as not to affect the test!

If you do not test on an empty stomach, it will affect the normal examination results, and you can not confirm the occurrence and development of the disease, so you need to be under the guidance of medical staff, with relevant auxiliary examination items, if it is a simple blood routine or trace elements, you generally do not need to fast, mainly for some blood sugar, blood viscosity or other indicators of liver and kidney function to check these items need to be fasted to test the doctor's advice and guidance.

Why do I have to have an empty stomach when I have a blood test? It turns out that the impact is so big.

Health Management Specialist of the People's Physical Examination Center:

Eating breakfast before the exam can cause alanine aminotransferase to rise. Since you have eaten, the results of the physical examination are not accurate, it is recommended not to take it, skip breakfast tomorrow, drink less or no water, do not exercise in the morning, and calmly wait for blood collection in the hospital, such a blood sample is a good specimen that reflects the real situation.

Elevated blood sugar level Your blood sugar level is not allowed, just know it yourself.

Indicators will be higher than normal.

Analysis:

Hello, whether the blood test after eating and drinking in the morning has an impact on the blood test depends on what items you are examining, you ask questions in liver disease, then about the examination of liver disease, hepatitis B two and a half, virus DNA, and other tests are not affected, liver function may be affected, eating and drinking may make the test of transaminase indicators high, blood lipids, blood sugar may also be high.

Guidance: It is recommended that you ask the doctor whether you need to have an empty stomach when you have an examination, and if you are not sure, try to go for the examination on an empty stomach.

Generally, the items that require a blood test on an empty stomach in the morning are:

1. Various blood chemical examinations. Blood glucose, total blood lipids, cholesterol, triglycerides, lipoproteins, serum protein electrophoresis, carbon dioxide binding capacity, various serum enzymes, A fetal globulin, serum immunoglobulin, mucin, etc.

2. Blood and liver function tests.

3. Blood and kidney function measurement.

4. Glucose tolerance test.

5. Serological and immunological examinations. Such as total complement, C3, rose petal test, antinuclear antibody, hepatitis B surface antigen, Phytococcus reaction, antistreptolysin "O".

Assays, rheumatoid factor tests, etc.

6. Various blood rheological measurements. Such as whole blood viscosity, plasma viscosity, serum viscosity, platelet viscosity, etc.

Some blood tests can be checked at any time, such as red blood cells, white blood cells, platelets, etc.

Some blood tests require blood tests to be taken on an empty stomach (skipping breakfast) in the early morning, such as kidney function, liver function, erythrocyte sedimentation rate, blood glucose, etc. This is because:

1. Avoid the influence of factors such as diet on some components in the blood.

Because food is absorbed by the gastrointestinal tract into the bloodstream and then transported from the bloodstream to the whole body, the concentration of certain components in the blood will increase, affecting the accuracy of the test results.

2. After eating, all kinds of digested food chylomicrons are quickly absorbed into the blood, making the blood appear turbid, commonly known as "fat blood", so that the examiner can not observe clearly.

3. The mood is relatively stable in the early morning, the body is in a basal metabolic state, and the results obtained can reflect the actual situation more realistically.

The so-called fasting refers to not eating after dinner and not eating early the next morning, in which case the blood test is the best.