Discover the vital role of blood drawing and testing

Jan. 31, 2024

Having blood drawn can be a daunting experience, but it’s crucial for supporting your health. So is knowing your blood type. From checking for certain diseases and conditions, to evaluating the function of your organs, to assessing heart disease risk, regular blood tests have various benefits. The person drawing your blood might not be your favorite person at that moment, but did you know there’s a term for their blood-collecting role? That’s right, they’re called a phlebotomist.

Phlebotomy describes the act of removing blood from a patient using a needle and a phlebotomist is a healthcare professional trained to collect blood samples for testing, and in some cases, they’re also responsible for handling other specimens, such as sputum, urine, and stool samples. Most blood is taken from veins, but phlebotomists are also trained on how to draw blood from capillaries. Phlebotomists also collect blood from donors for those in need of blood transfusions.

The phlebotomist's blood draw process typically includes:

Begin by applying a tourniquet (stretchy band) to the upper arm to make it easier to find a vein to draw blood from
Disinfecting the area where the blood will be drawn
Inserting a needle into the vein and attaching one or more vials to collect the blood, depending on what blood test is being ordered
Releasing the tourniquet and removing the needle from the vein
Stop any bleeding by applying minimal pressure to the area, and then putting a Band-Aid over the location of blood draw

There are a variety of blood tests a phlebotomist might draw blood for, including:

Complete Blood Count (CBC)

The complete blood count (CBC) is one of the most common blood tests and is often administered as part of a routine checkup. This test measures many different parts of your blood, including red blood cells, white blood cells, and platelets. CBC tests are used for testing anemia, bleeding disorders, blood cholesterol, blood clotting disorders, sickle cell disease, and thalassemia. Your healthcare provider should discuss your results with you once they are received, and will advise you further if your results are outside the normal range for your group.

Blood Chemistry Tests/Basic Metabolic Panel

The basic metabolic panel (BMP) is a group of tests that measure different naturally occurring chemicals in the blood, and are usually done on the fluid (plasma) part of blood. BMP tests are used for testing heart failure and high blood pressure, and can give providers information about your organs, such as the heart, kidneys, and liver. The BMP includes blood glucose, calcium, and electrolyte tests, as well as blood tests that measure kidney function. Some of these tests require you to fast before the test, and others don't.

Blood Enzyme Tests

Enzymes are chemicals that help control chemical reactions in your body, and there are many types of blood enzyme tests, including some blood enzyme tests that may be used to check for a heart attack. Troponin and creatine kinase (CK) tests are the blood enzyme tests used to check for a heart attack. Blood levels of troponin go up when a person has muscle damage, including damage to the heart muscle, and an enzyme called CK-MB is released into the blood when the heart muscle is damaged. High levels of CK-MB in the blood can mean that you've had a heart attack.

Lipoprotein Panel

A lipoprotein panel, also called a lipid panel or lipid profile, measures the levels of LDL and HDL cholesterol and triglycerides in your blood, and is used to test for Atherosclerosis, Blood Cholesterol, Coronary Heart Disease, and High Blood Triglycerides. Cholesterol and triglyceride levels that are higher or lower than normal may be signs of higher risk of coronary heart disease. A lipoprotein panel gives information about your total cholesterol, LDL ("bad") cholesterol, and HDL (“good”) cholesterol. LDL cholesterol is the main source of cholesterol buildup and blockages in the arteries, whereas HDL cholesterol helps decrease cholesterol blockages in the arteries. Lipoprotein panels also provide details about your Triglycerides, which are a type of fat in your blood. Most people will need to fast for 9 to 12 hours before a lipoprotein panel.

Blood Clotting Tests

Blood clotting tests, also known as coagulation panels, are tests that check proteins in the blood that affect the blood clotting process, and are used to test for bleeding disorders, blood clotting disorders, and platelet disorders. Levels that are higher or lower than normal might suggest that you're at risk of bleeding or developing clots in your blood vessels. Blood clotting tests also are used to monitor people who are taking medicines to lower the risk of blood clots.

Bone Marrow Tests

Bone marrow tests are used to check if the bone marrow is healthy and making normal amounts of blood cells, and are used to test for Anemia and Platelet Disorders. There are two types of bone marrow tests, aspirations and biopsy. Aspiration tests collect a small amount of bone marrow fluid, whereas a biopsy test collects a small amount of bone marrow tissue. Oftentimes, biopsy tests are done at the same time as the aspiration test. These tests can help find the cause of low or high blood cell counts, and also play a pivotal role in checking how well treatments for certain types of cancers, such as leukemia or lymphoma, are working.

Sources:

NIH: National Heart, Lung, and Blood Institute: Blood Tests