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If you were required to fast prior to the blood test, you’ll want to bring a snack for after the test. Also bring a bottle of water and a snack that doesn’t require refrigeration. This will tide you over until you are able to eat a meal.  Peanut butter crackers, a peanut butter sandwich, a handful of almonds or walnuts, or whey protein are all easy to transport and will give you some protein and calories until you can get a meal. If you forgot to bring anything to eat, ask the staff where you have had blood drawn. They may keep cookies or crackers around for just this purpose. Some tests can be finished within 24 hours while others can take a week or more if the blood must be shipped to a special laboratory. Talk with your doctor about the process used to deliver the results of the blood test. In some cases the office will not notify you if the results are all within normal limits. If the blood is sent off, also ask how long it will be before the office gets the results from the laboratory.  Ask to be notified, even if the results are normal. This will ensure that your results don’t "fall through the cracks" and you aren’t notified if the results are not normal. Call the doctor’s office 36 to 48 hours after the results should have arrived if you are not notified. Ask your doctor’s office if they use an online notification system. You may be given a website to register through so your results can be delivered digitally to you. The most common side effect to having blood drawn is a bruise, or hematoma, at the site where the needle went in. The bruise can show up immediately or within 24 hours after the blood was drawn. Some of the factors that contribute to the formation of a hematoma include blood leaking out of the opening when a needle goes through a vein, which leaks into the surrounding tissue. They can also be caused by bleeding disorders or anticoagulant medications, which increases the risk that a bruise or hematoma will occur where the blood is drawn.  Applying pressure over the area where the blood was drawn for five minutes, which is longer than necessary to stop the area from bleeding to the outside, will often help to reduce the risk of a hematoma, or a collection of blood outside of a blood vessel.  Hemophilia is the most well-known bleeding disorder, but it is also fairly rare. It comes in two forms - A & B. Von Willebrand disease (VWD) is the most common bleeding disorder, and affects how your blood clots.  Patients should let their doctor and phlebotomist know they have a bleeding disorder when they get their blood drawn. There are certain situations that can lead to inaccurate results on your blood tests. Prolonged tourniquet application can lead to a pooling of blood in the arm or extremity where the blood was being drawn. This increases the concentration of blood and increases the potential for false positive or negative results on the blood tests.  The tourniquet should be in place for no longer than one minute to prevent pooling, also called hemoconcentration. If longer than a minute is needed to locate a choice vein, then the tourniquet should be released and reapplied after two minutes and only immediately before the needle is inserted. Hemolysis is a problem with the blood sample and not a complication which you experience. Hemolysis happens when the red blood cells rupture and other components spill into the blood serum. Hemolyzed blood is not acceptable for testing and another blood sample will have to be drawn. Hemolysis is more likely to occur when:  The tube is mixed vigorously after being removed from the needle. Drawing blood from a vein near a hematoma. Using a smaller needle which damages the cells as they are drawn into the tube. Excessive fist clenching during the blood draw. Leaving the tourniquet on for more than one minute.
Eat a snack. Ask how long you’ll wait for results. Notice a bruise. Ask about a possible result complications. Discuss hemolysis with the phlebotomist.