Do I need to be on an empty stomach for blood draw

Blood test is the most common examination method. We usually need to have blood test during physical examination. At this time, we need to fast and cannot eat within 8 hours. However, not all blood tests require fasting. There are many items that do not require fasting. For example, when women take blood test for pregnancy, they do not need blood test. You must understand this knowledge before the examination. Let us learn about this aspect.

Do I need to be fasting for blood draw?

There is no need to fast for 146 blood tests. It is reported that Beijing Friendship Hospital currently has more than 480 clinical testing items. The outpatient department, together with the testing department and clinical departments, conducted sufficient discussion and, based on the characteristics of the testing items, selected 146 testing items for full-time blood drawing. Blood tests for these tests do not require fasting and can be performed at any time before 4 p.m. every day. The 146 tests include routine blood tests, 5 items of hepatitis B, 8 items of infection, 5 items of endocrine, 7 items of virus, carcinoembryonic antigen, Helicobacter pylori antibody test, anemia series, and thermal research institute projects. Take the four infectious disease tests as an example. These are blood tests that every patient who is hospitalized, undergoes surgery, or has an endoscopic examination needs to undergo. In the past, these four tests required at least three tubes of blood, but now only one tube of blood is required.

Blood test precautions

1. Do not exercise before blood draw

It is not advisable to do strenuous exercise in the morning, because strenuous exercise can also change the concentrations of various blood indicators and affect the measurement results. For example, an old man received a report that his creatine kinase (Ck) level was over a thousand. He was so excited that he came to consult. In the end, he said that he rode a bicycle for half an hour in the morning, rode a little fast and uphill, and now his legs are sore. It is very likely that Ck released by skeletal muscle interferes with the results. If you have performed long and strenuous exercise in the recent days and have obvious soreness in your hands and feet, and the test results are somewhat abnormal, then it is recommended that you come back for a check-up in a few days.

2. Wear loose clothing

On the day of blood collection, wear loose clothing and do not wear clothes with sleeves that are too small or too tight to avoid having sleeves that cannot be rolled up during blood collection, or having difficulty in stopping bleeding and hematoma in the arm blood vessels due to tight sleeves after blood collection. This should be paid more attention to in winter.

3. Bring some candy

If you have a history of fainting at the sight of blood, it is best to inform the blood-drawing nurse in advance, and you can bring some candy or chocolate with you when your blood is drawn. If you experience symptoms of blood phobia such as dizziness, blurred vision, fatigue, etc. after blood drawing, you can drink a small amount of sugar water or eat candy, lie down and rest for a while, and then undergo other examinations after the symptoms are relieved.

4. Post-bleeding treatment

After drawing blood, use sterilized cotton wool to compress the area where blood was drawn. Local pressure should be applied at the needle hole and 2 cm upward for 3-5 minutes. Do not rub it to avoid causing subcutaneous hematoma. Because individual coagulation times vary, some people may need longer pressing times. If there is a tendency to bleed, the pressing time should be appropriately extended. Some people stop applying pressure when they see no more blood oozing out of the epidermis, which may cause bruising due to subcutaneous bleeding. If bruising occurs, apply a hot towel after 24 hours.