Why do you need an empty stomach blood test?

Which tests need to draw blood on an empty stomach in the morning? Generally, the items that need fasting blood test in the morning are: 1. Various blood chemistry tests. Blood sugar, total blood lipid, cholesterol, triglyceride, β-lipoprotein, serum protein electrophoresis, carbon dioxide binding capacity, various serum enzymes, alpha-fetoprotein, serum immunoglobulin, mucin, etc. 2, blood liver function test. 3. Determination of blood and renal function. 4. Glucose tolerance test. 5. Serological and immunological examination. For example, total complement, C3, rose petal test, antinuclear antibody, hepatitis B surface antigen, widal reaction, determination of anti-streptolysin "O" and examination of rheumatoid factor. 6. Measurement of hemorheology. Such as whole blood viscosity, plasma viscosity, serum viscosity and platelet viscosity. Why do you need an empty stomach blood test? Some blood tests can be checked at any time, such as red blood cells, white blood cells and platelets. Some blood tests need to be carried out on an empty stomach (without breakfast) in the morning, such as renal function, liver function, erythrocyte sedimentation rate and blood sugar. This is because: first, avoid the influence of diet and other factors on some components in the blood. Because food is absorbed by gastrointestinal tract into blood, and then transported to the whole body by blood, the concentration of some components in blood will increase, which will affect the accuracy of test results. Secondly, after eating, all kinds of digested food chyle particles are quickly absorbed into the blood, which makes the blood appear turbid, usually called "fatty blood", which makes it impossible for inspectors to observe clearly. Third, the mood is relatively stable in the morning, and the body is in a state of basal metabolism. The results can truly reflect the actual situation. Fasting means not eating after dinner and not eating breakfast the next morning. In this case, blood test is the best method. Will blood test affect children's health? In recent years, we have found clinically that many parents are unwilling to let their children have blood tests. When they saw the red blood in the blood vessels flowing into the needle, their parents were very distressed and thought it was too harmful to their children's health. Will blood test affect children's health? We know that the total blood of normal people is about 8% of body weight. For example, the total blood volume of a child weighing 20 kg is 1600 ml, and usually only 1 ~ 3 ml is needed for blood test, which is less than 0.2% of the whole body blood! A healthy person's blood loss at a time will not exceed 10% of the whole body weight, which will not cause any harm to the body, let alone a small amount of blood used for testing. Blood tests are very helpful for the diagnosis and treatment of some diseases, and have no influence on children's health, especially now, with the improvement of detection technology and the popularization of various micro-detection technologies, the amount of blood needed for the same test is gradually decreasing. If the doctor asks the child to do necessary blood tests, parents should actively cooperate and do a good job in blood collection. ……