You do not need to fast to have a coagulation test. The coagulation test is a test to see if the blood clotting function is good, and it is done by drawing blood from a vein. If you only check the coagulation four, but not the blood lipids, liver function, kidney function, fasting blood sugar and other items, you do not need to fast. The items that need to be tested on an empty stomach are the ones where eating and drinking have a greater impact on the test results, and these items are not reliable if you go after a meal. Except for emergencies or other special reasons, it is usually necessary to go for blood tests after 12 hours of fasting. There are some laboratory tests, such as routine blood tests, four blood coagulation tests, five or six hepatitis B tests, hepatitis C antibodies, glycated hemoglobin, etc. These tests can be done on an empty stomach or not, and the difference between the results on an empty stomach and after a meal is not significant. It’s better to have your blood drawn for multiple tests at the same time, or to go on an empty stomach.