5 Key Tips for a Successful Blood Draw

By Mundi Attinasi, MD

If you are feeling nervous about having your blood drawn, we recommend getting plenty of rest and practicing breathing techniques to help you feel calmer before and during the appointment; and please let your phlebotomist know your concerns so they can make your visit more comfortable.

  1. Drink plenty of water and come well rested. Getting a good night’s sleep and increasing your blood volume by drinking water can help make it easier for the phlebotomist to access your vein.
  2. Avoid excessive consumption of caffeinated beverages such as coffee, soft drinks or tea the day before your appointment. These can cause dehydration and make it difficult to draw your blood.
  3. Consider fasting. For many blood tests, including those done by Lookout Health, you may need to avoid eating for about 8-12 hours beforehand (oftentimes overnight). Verify with your provider as time may vary based on the test. Please note that you may still drink water when fasting.
  4. Wear short sleeves or layers so you don’t have to undress or awkwardly pull your arm from your sleeve to expose your vein.
  5. Take your prescribed medications as directed with a small sip of water before your appointment, unless a healthcare professional advises you otherwise.

Biotin and Laboratory Testing

Lookout Health wants you to be aware that some laboratory tests can be affected by high levels of biotin (Vitamin B7) in your blood sample. Ingesting high levels of biotin can significantly interfere with certain laboratory tests and cause incorrect test results. Biotin can be found in multivitamins, prenatal vitamins, and dietary supplements marketed for hair, skin, and nail growth.

Biotin in patient samples can cause falsely high or falsely low results, depending on the test. Incorrect test results may lead to inappropriate patient management or misdiagnosis. Please inform your phlebotomist if you are taking a biotin supplement and talk to your doctor for more information when adding biotin to your diet.


Dr. Attinasi is the Chief Medical Officer for Lookout Health. She is a board certified pediatrician with 20 years of experience as a clinical health provider. For further information about our health and wellness services, please contact Lookout Health customer service for questions: support@lookouthealth.com.