How to Prepare for Blood Work to Get the Most Accurate Result

WHY IT MATTERS: Regular blood work is an essential part of optimizing your health, and it’s one of the first steps in your Marek Health journey. However, failing to prepare for your blood work can skew your results.

From following any necessary fasting guidelines to avoiding certain foods and activities to ensuring you’re well-hydrated, we’ll share the best ways to prepare for blood work to get the most accurate readings.

Do I have to fast before blood work?

Many blood tests require fasting, meaning you can’t eat or drink anything besides water for 8-12 hours beforehand. Why? Because fasting helps you get the most accurate results.

Nutrients in food and drinks are absorbed into your bloodstream. Tests that measure the nutrients in your blood can be skewed by micronutrients, carb, protein, and fat levels in your food. That’s why it's essential to not eat or drink anything 8-12 hours before getting blood work done.

Your doctor will tell you if you need to fast and for how many hours before your test.

If you are getting any of the following blood tests, you are likely required to fast:

• Blood glucose tests

• Metabolic panel tests

• Lipid panels (total cholesterol, HDL, LDL, triglycerides, apolipoproteins)

If your healthcare provider orders a blood test without mentioning fasting, consider asking if you should fast.

How else can I prepare for blood work?

Beyond typical fasting, there are a few important ways to prepare for blood work so you get the most accurate results.

Hydration is key

Staying hydrated is vital when getting blood work done. Drinking plenty of water the day before and the day of your blood work keeps your veins well-hydrated, making them easier to locate. Hydration also helps maintain normal blood thickness and pressure, which can prevent complications during and after testing. 

Avoiding certain supplements, foods and drinks

Many physicians recommend avoiding Vitamin B or Biotin supplements at least 72 hours before your blood draw. (Check your daily multi-vitamin, if you take one, to see if either is listed on the label.)

Regardless of whether you have to fast, you should avoid eating greasy, fatty, or rich food the day before your test. These foods can temporarily raise your cholesterol levels and alter your test results.

You also must avoid beverages other than water, including coffee, tea, and alcohol. Coffee and alcohol act as diuretics, which can dehydrate you and lead to inaccurate test results.

Activities to avoid

You should avoid exercising for 12 to 24 hours before a blood test. Strenuous exercise can alter blood results and impact cholesterol and glucose levels. You should also avoid chewing gum and smoking. 

Does it matter when I get blood work done?

In short, yes. The best time to get blood work done is between 7 AM and 9 AM.  Many hormone and enzyme levels fluctuate throughout the day, so they should be done in the morning to get the most accurate results. Additionally, this time frame is recommended particularly for fasting blood tests, so most of your fasting time is spent while you’re asleep. 

For women with a regular menstrual cycle, the timing of blood work matters even more. Biomarkers like lipids, iron, vitamin D, and hs-CRP fluctuate throughout your menstrual cycle, so getting your blood drawn at the same point in your cycle each time will provide more accurate results. Your healthcare provider may advise that you get blood work done during a specific part of your cycle to optimize your results. 

Start Your Marek Health Journey

After following these steps, you’ll be prepared to get the most out of your Marek Health diagnostic labs. Schedule a free discovery call today.

Disclaimer: This blog post is intended for informational purposes only and should not be considered medical advice. Consult with a healthcare professional before making any changes to your wellness routine.