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Blood Work Basics: What to Know About Your Test

There are a few dif­fer­ent stan­dard blood tests gen­er­al­ly ordered by your physi­cian. Many blood tests don’t require any spe­cial prepa­ra­tion and take only a few min­utes. Oth­er tests may require fast­ing (not eat­ing any food) for 8 to 12 hours before the test.

Make sure you talk to your physi­cian and under­stand what type of test you are hav­ing and its requirements.

Before Your Blood Test

  • Drink plen­ty of water! Many tests want you to avoid all food and bev­er­ages — except water. If you drink a lot of water, your blood draw may go more smooth­ly as blood is made up of 50% water. This makes your veins plumper and eas­i­er to get a blood sample.
  • Bring a healthy snack and eat it after your test.
  • If you have to fast, try to go to the lab first thing in the morn­ing. That way you have a short­er por­tion of your day to tol­er­ate an emp­ty stomach.

Dur­ing Your Blood Test

No one looks for­ward to a blood draw, but the pro­ce­dure is usu­al­ly brief and unevent­ful. Many peo­ple are in and out of the lab in about 15 minutes.

  • Blood is usu­al­ly drawn from a vein in your arm or oth­er part of your body using a nee­dle. To make it eas­i­er for the per­son who draws your blood (phle­botomist) to access your vein, wear a shirt with short sleeves or some­thing with sleeves that eas­i­ly roll up.
  • The phle­botomist might tie an elas­tic band (tourni­quet) around your bicep and ask you to make a fist. Doing this can make the veins in your arm more acces­si­ble and eas­i­er to insert the nee­dle to avoid mul­ti­ple sticks”.
  • The nee­dle that goes into your vein is attached to a small test tube. The phle­botomist will remove the tube when it’s full, and the tube seals on its own. The nee­dle is then removed from your vein.
  • If mul­ti­ple sam­ples are need­ed, more than one test tube might be attached to the nee­dle before it’s with­drawn from your vein.
  • If you’re ner­vous or scared, it can help to look away or talk to some­one to dis­tract your­self. You might feel a slight sting when the nee­dle goes in or comes out, but gen­er­al­ly does­n’t hurt while the nee­dle is inserted.

After Your Blood Test

  • When the nee­dle is with­drawn, you’ll be asked to apply gen­tle pres­sure with a piece of gauze ban­dage to the site. This helps to stop the bleed­ing and may help pre­vent swelling and bruising.
  • Keep your arm straight, as bend­ing your arm may cause bruising.
  • Hold pres­sure on the spot where the nee­dle was insert­ed. The phle­botomist will check for con­tin­ued bleed­ing and apply a ban­dage if it has not stopped. You may want to keep a ban­dage on for a few hours.
  • If bleed­ing occurs, ele­vate your arm and apply pres­sure to the ban­dage for at least five min­utes. If you devel­op a bruise, apply ice wrapped in a tow­el or cloth to the area for 15 – 30 min­utes sev­er­al times a day for the first day. Warm, moist heat can be used instead of ice after the first day. If you expe­ri­ence more than minor dis­com­fort after the first day, you may want to call your physi­cian for advice.

Usu­al­ly, you don’t need to do any­thing else after a blood test. If you use a DMG lab and have a DMG physi­cian, your doc­tor will receive your results auto­mat­i­cal­ly through DMG’s elec­tron­ic med­ical record. It’s impor­tant that you fol­low-up with your doc­tor to dis­cuss your test results. 

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