Most people know that the fasting test, that fasting test should be empty how long, there is a time limit?

A fasting test is generally defined as having been fasting for 10 to 12 hours in the morning.

Patients are often told to fast for at least eight hours and not to drink for six hours before the test.

That means no food from 2200 the night before. (Note that "anything," snacks, late-night snacks, and milkshakes are not allowed.)

However, depending on the medical checkup program, the checkup time varies, so the required fasting time and duration also varies, so the required method of fasting must be adjusted according to the medical checkup program and the doctor's specific instructions.

Different checks, the requirements for drinking water are not the same. For example, to do gastroenteroscopy, really should not drink water. Hard to drink water, after anesthesia can easily cause choking and suffocation. On the contrary, do urological or gynecological ultrasound to drink a lot of water in advance, because these tests need to hold urine, bladder expansion, the organs to be examined as far as possible pushed to the abdominal wall to facilitate the examination. If the physical examination program does not have special requirements, you can drink a little water before the examination, in order not to feel thirsty for good.

Venous blood test

The need to fasting blood test items include (but not limited to):

Glucose metabolism: fasting glucose, fasting insulin, fasting C-peptide, etc..

Lipids: total cholesterol, glycerol, HDL cholesterol, LDL cholesterol, Lipoprotein A1, Lipoprotein B, Lipoprotein A, Lipoprotein E, and free fatty acids.

Blood rheology;

Markers of bone metabolism: bone calcium, type I collagen, carboxy-terminal peptide special sequence, bone alkaline sulfatase, etc.

Platelet aggregation rate.

Before drawing blood, normal people's emotional state is more stable in the early morning, and the body is largely in the state of basal metabolism in the fasting state, so the examination items can be placed within the normal reference value. So the fasting blood test is to unify the state, in order to be able to repeatedly check the results of the comparative judgment. This is the only way to have a meaningful examination.

Note to grasp the reasonable time of fasting, fasting blood collection is the best time between 8:00 am and 9:00 am, the latest should not exceed 9:30 am. Too late will be affected by physiological and endocrine hormones, such as blood glucose can be reduced with the prolongation of fasting time, if due to prolonged starvation so that the blood glucose is reduced, not only affects the judgment, but also the risk of hypoglycemia.