How to Prepare to Have Your Blood Drawn

One of the most important things you can do to prepare for having your blood drawn, is to make sure you are well hydrated.

“If you're having blood drawn, unless you've been told not to eat or drink anything by your provider make sure you are well-hydrated,” says Jerry Simmers, director of laboratory services at NorthBay Healthcare. “A ‘fasting’ blood sample normally means no food and flavored drinks for 12 hours, because it may affect some lab tests such as glucose or cholesterol, however drinking water does not affect the results of those tests,” he noted

Being well-hydrated makes it far easier for the person who is taking the patient’s blood to find a vein that can easily be punctured and far easier for the patient because their veins will be much easier to find and access, explained Simmers.

Ideally, start drinking more fluids the day before your blood draw, and continue to drink water before you have your blood drawn. Excessive amounts aren't necessary; most sources ecommend that an adult drink 64 ounces of water per day for good health, which is more than adequate for having your blood drawn. Limit caffeine, which acts as a mild diuretic increases the amount of urine you produce.

Simmers offered the following tips for patients:

1. Breathe

Don't hold your breath while your blood is being drawn. Some people hold their breath in anticipation of the insertion of the needle, which doesn't help at all if you're feeling faint. Keep breathing at your normal rate and depth, and you'll be far less likely to feel lightheaded during a blood draw.

2. Be Honest

If you are someone who has fainted in the past when donating blood or having your blood drawn, be sure to tell the person who will be drawing your blood. If there is the slightest chance of fainting during a blood draw, positioning is key. Both of NorthBay’s laboratories have special chairs that completely recline and allow you to lie down during the blood draw.

3. Don't Look

If having your blood drawn makes you feel queasy, don't watch while your blood is drawn. For some, the sight of blood is the problem, so not watching while blood is collected can easily solve that problem. Look away, and concentrate on whatever will distract you from the procedure.

4. Sit Still

If you're moving and wiggling while someone is attempting to draw your blood, it's likely that he will have to make more attempts to obtain the sample. Sit as still as possible. Even if you are nervous, it's important to refrain from wiggling and fidgeting or you could potentially add to the number of pokes required to draw your blood.