1, the day before the blood draw do not eat too greasy, high-protein food, avoid drinking a lot of alcohol. The alcohol content in the blood will directly affect the test results. 2.After 8:00 p.m. the day before the physical examination, you should start fasting for 12 hours to avoid affecting the test results. 3, blood should be relaxed when drawing blood, to avoid the contraction of blood vessels caused by fear, increasing the difficulty of blood collection. 4.After blood sampling, local pressure at the needle hole is required for 3-5 minutes to stop bleeding. Note: Do not rub to avoid causing subcutaneous hematoma. 5.Pressure time should be adequate. The clotting time varies from person to person, and some people need a slightly longer time to clot. So when the skin surface does not seem to bleed immediately stop compression, may not completely stop bleeding, and blood seepage to the subcutaneous cause bruising. Therefore, longer pressure is necessary to stop bleeding completely. If there is a tendency to bleed, the compression time should be extended. 6.After blood sampling, symptoms of dizziness such as dizziness, dizziness and weakness should be immediately laid down, drink a small amount of sugar water, and wait for the symptoms to be relieved before conducting physical examination. 7.If local bruising occurs, wet compress with warm towel after 24 hours can promote absorption.