A checklist for your next blood test
Your blood holds a wealth of information about what's going on in your body. That's why we recommend scheduling regular tests to check up on the state of your health. So If you have a blood draw coming up, there are a few things you should keep in mind to get accurate results and make the process go as smoothly as possible. In this article, we'll share a few tips on how to prepare for an easy blood draw, how to make it a smooth experience, and what to do after.
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When and why to fast for a blood draw?
Getting ready for a blood test often requires fasting for up to 12 hours before going in for the test. When you eat and drink certain foods, they get absorbed into your bloodstream during the digestion process and could alter your test results. But not every blood draw requires fasting. Your healthcare provider will inform you before your appointment on whether you need to and how long you should abstain.
Fasting is particularly important before a glucose test, which measures the amount of sugar (glucose) in the blood. If you eat before this test, your blood sugar levels will normally rise and alter the results. Other blood tests that require fasting include:
- Liver panel
- Lipid panel to test for cholesterol levels
- Basic metabolic panel
Tips on how to prepare for a blood draw
Going in for a blood draw is no big deal, but can still be stressful for many of us. If you are nervous, you should know that it's a quick and straightforward process that only takes a few minutes. To ensure that your blood draw is seamless, here are a few things you should do before.
Fast for 12 hours if recommended by your healthcare provider
Some blood tests (such as the aware health check) will require you to fast beforehand for 12 twelve hours for accurate results. Fasting means you don't eat or drink anything but water. You can eat right after your blood draw. If you forgot and had food right before your test, share this with your phlebotomist. In certain cases, your test might be rescheduled.
It's essential to stay hydrated, especially on the day of your blood draw. Drinking plenty of water makes it easier for your nurse or phlebotomist to find a vein and draw blood from you. Your blood will flow more freely, filling up the vial quicker.
Avoid vigorous exercise
While you can engage in light exercise, avoid vigorous exercise right before your blood draw. Depending on the parameters to be tested, intense exercise can raise specific biomarkers – such as CRP, creatine kinase, cholesterol and liver enzymes. For your blood test results to be most accurate, the blood draw should be done when your body is rested.
It will help if you avoid alcohol for up to 24 hours before your blood draw. Like rigorous exercise, alcohol can elevate specific biomarkers in your blood – such as glucose and triglyceride. Elevated glucose levels can give false test results for conditions like diabetes, while high triglyceride levels could give inaccurate results for conditions like metabolic syndrome.
Pause any supplements
Supplements go into your bloodstream, and depending on the supplement, they can linger for hours to days. If you have adequate notice of an upcoming blood draw, it'll be a good idea to pause any supplements until right after. However, if you haven't, not to worry; a good rule of thumb is pausing supplements for about 24 hours. If you are taking biotin supplements, you should stop taking them for at least three to seven days.
Take or pause medication as recommended by your doctor
If you are taking medication prior to your blood draw, you should discuss this with your doctor. Some can affect the results of your blood test. The most common medications that may interfere with blood tests include thyroid medication and diabetes medication. Talk to your healthcare provider to see if it might be best to take the medication after the test to avoid skewed results.
Schedule your blood draw in the morning
If fasting is required for your test, it’s more convenient to fast overnight while asleep and get your blood test done first thing in the morning—that way, you are not tempted to break your fast. Some blood tests must be done at specific times, like at noon or in the afternoon, so always wait for instructions from your health provider or ask in case of doubt.
What to do during the blood draw
If you are nervous or anxious about your blood draw, don't hesitate to share your worries with the person drawing your blood. They can talk you through the process and try to put you at ease. Other tips to make the process easier include:
- Ask questions: Feeling anxious during your first blood draw is normal. Let the nurse or phlebotomist know and ask as many questions as possible about the process. This can help put your fears at ease.
- Suggest a spot for the draw: If you've gotten blood draws in the past, you might already be familiar with which spot works best for you. This is especially helpful if your phlebotomist has difficulty locating an appropriate vein.
- Ask for numbing medication: For most people, the worst part of a blood draw is getting pricked by the needle. Numbing medicines can significantly reduce any discomfort.
- Look away and take deep, steady breaths: Looking away is a simple but effective trick to calm your nerves while your blood is drawn. It will be over before you know it.
- Listen to music: Listen to your favorite song on your phone to distract yourself. Researchers at Stanford University have said that "listening to music seems to be able to change brain functioning to the same extent as medication".
- Bring a friend to support you: If you are nervous about getting your blood test done, have a friend hold your hand to keep you calm.
- Keep warm: Low temperatures shrink your veins, making it more difficult for the phlebotomist. So stay warm.
What to do after the blood draw
After a blood draw, there isn't much to do but go home and wait for your blood test results. You might feel a little lightheaded right after the draw, but this is nothing to worry about. Remember, you've probably just fasted for twelve hours. Eating a hearty meal, resting, and hydrating will help.
- Eat a quick snack and drink water to help replenish lost energy and fluids, especially after fasting overnight. In the days after your blood draw, eating foods rich in nutrients and vitamins can be helpful.
- Eat iron-rich foods if you had a lot of blood drawn for multiple tests or if you do frequent blood tests. Foods such as spinach, liver, red meat, and beans are all rich in iron. Adding foods rich in vitamin C, such as citrus fruits, strawberries, and broccoli, can also help your body absorb iron better.
- Avoid strenuous exercise if the spot where the blood was drawn continues to bleed. Intense physical activity right after might cause the site to keep bleeding.
- Apply a cold compress if you experience soreness on the spot of the draw. But if it doesn't bother you, it'll go away in no time.
- Apply a warm cloth to the affected area about two days after your blood draw if you have bruising. The warm cloth will stimulate blood to flow and help the healing process.
If the blood draw went as planned, you should be perfectly fine and not experience any side effects. However, if you have any of the following symptoms after a blood draw, contact your healthcare provider:
- Stiffness in the arm the blood was drawn from
- Intense pain in your arm
- Tingling in your arm
- Redness or inflammation around the area where the blood was drawn
- Severe swelling of your arm
The bottom line
Getting a blood draw can be a breeze once you know what to expect and how to prepare. Download our list to have it handy for your next appointment. Staying hydrated, fasting for specific tests, and avoiding alcohol, supplements, and intense exercises before a draw are essential for accurate results. If you have any worries or fears about the process, talk to the nurse or phlebotomist before they begin the draw. Try to remain calm and relaxed throughout the entire process; it'll be over before you know it.
Disclaimer: aware's products and services are designed to enhance a healthy lifestyle, but they are no substitute for professional medical advice. Our content and media do not intend to diagnose, cure, or treat any medical condition.
- PhlebotomyU. Which blood tests require fasting beforehand. Accessed July 18, 2022. Which-blood-tests-require-fasting
- National Institute of Mental Health (NIMH). What is a blood draw? Published February 10, 2021. Accessed July 4, 2022. What-is-a-blood-draw
- National Library of Medicine. Fasting for a blood test. Published March 3, 2021. Accessed July 5, 2022. https://medlineplus.gov/lab-tests/fasting-for-a-blood-test/
- Upstate Medical University. Preparing for your blood donation with water. Published October 10, 2013. Accessed July 5, 2022
- Foran, S.E. & Lewandrowski, K.B. & Kratz, A. (2003). Effects of exercise on laboratory test results. Laboratory Medicine. 34. 736-742. Accessed July 6, 2022 10.1309/3PDQ-4AH6-62AT-B6HM
- Stanford Report. Feeling the beat: Symposium explores the therapeutic effects of rhythmic music. Published May 31, 2006. Accessed July 18, 2022 brainwave-053106.html
- Sathyanarayana Rao TS, Christopher R, Andrade C. (2017) Biotin supplements and laboratory test results in neuropsychiatric practice and research. Indian Journal of Psychiatry. 59(4):405-406. Accessed July 8, 2022 10.4103/psychiatry.IndianJPsychiatry_454_17.
- National Institutes of Health. Iron and blood donation. Published April 29, 2022. Accessed July 7, 2022 https://clinicalcenter.nih.gov/blooddonor/iron.html
September 10, 2022
September 10, 2022