If you’ve ever had a blood test, you may have wondered, perhaps as that needle was getting closer and closer, what exactly is the point of this? As it turns out, quite a lot. The standard blood test measures many things. There are also specific blood tests a doctor might order based on a person’s health history or a particular medication he or she is taking. A common blood test is the CBC, which stands for complete blood count. In this test, doctors can obtain counts of red blood cells (RBC) and white blood cells (WBC).
Healthy blood has 4.2 – 6.9 million RBC’s per cubic millimeter of blood and 43,000 108,000 WBC’s per cubic millimeter. That’s a lot of cells!
If a person has anemia, part of the CBC called the mean corpuscle volume (MCV) can help determine the cause. A CBC can also determine the amount of platelets in the blood, a very important number since platelets are needed for blood clotting. A range of 150,000 – 350,000 platelets per milliliter of blood is considered normal. Blood tests also commonly test for cholesterol levels. Cholesterol can clog the blood vessels, making it harder for blood to get around the body. This can lead to heart disease and heart attack. Healthy people generally have less than 225 milligrams of cholesterol per deciliter of blood, although the acceptable amount can increase as people age.
It is important to realize that there are some healthy people who will have blood tests results outside the “normal” range, and some people who are not healthy at all in spite of being within normal limits. This is why blood tests should be interpreted by a doctor or other medical professional. The thing to remember, however, is that blood tests are checking for important medical conditions. So even if it hurts a little for a moment, the test can do an awful lot of good.