What does cbc test for

You may need this test if your healthcare provider thinks you have a blood disorder. You may need this test if you have:. You may also have this test if your healthcare provider thinks you may have a certain disease or condition. Or you may have this test as part of a routine exam to check your health. The test may also be used to see how well certain treatments are working. Your healthcare provider may also order other tests if your results for this test are abnormal. These may include other blood tests, urine tests, and bone marrow or spinal fluid tests.

Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. White blood cells WBC : 4. Hemoglobin Hb or Hgb : The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand.

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded.

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Top of the page. Test Overview A complete blood count CBC gives important information about the kinds and numbers of cells in the blood, especially red blood cells , white blood cells , and platelets. White blood cell types WBC differential. Red blood cell RBC count. Hemoglobin Hgb. Red blood cell indices. Platelet thrombocyte count. Mean platelet volume MPV. There are many other reasons that a doctor may want this blood test, including to: Find the cause of symptoms such as fatigue, weakness, fever, bruising, or weight loss.

Check for anemia. See how much blood has been lost if there is bleeding. Diagnose polycythemia. Check for an infection. Diagnose diseases of the blood, such as leukemia. Check how the body is dealing with some types of drug or radiation treatment.

Check how abnormal bleeding is affecting the blood cells and counts. Screen for high and low values before a surgery. See if there are too many or too few of certain types of cells. This may help find other conditions. For instance, too many eosinophils may be a sign of an allergy or asthma. A blood count can give valuable information about the general state of your health. How To Prepare In general, there's nothing you have to do before this test, unless your doctor tells you to.

How It Is Done A health professional uses a needle to take a blood sample, usually from the arm. How It Feels When a blood sample is taken, you may feel nothing at all from the needle. A CBC is responsible for testing the cells. There may be several terms on the results you are not familiar with. The normal ranges listed below are for a healthy adult. Ranges vary depending on sex, age, and other conditions. Hemoglobin is a protein that carries oxygen around the body.

Its normal range is Hematocrit indicates the proportion of the count that are red blood cells. A normal range is a 0. MCV is mean cell volume, and should be 74 to 87 fL. MCH is the amount of hemoglobin per blood cell, and a normal range is 24 to 29 pg.

WBC stands for white blood cells, and indicates the total number of white blood cells in the blood. A White blood cell normal range is 4. Neutrophils, lymphocytes, monocytes and eosinophils are all types of white blood cells. Their absolute counts should be:. A CBC with differential is also known as a blood differential test, white blood differential count, or leukocyte differential count.

A few kids and teens have a strong fear of needles. If your child is anxious, talk with the doctor before the test about ways to make the procedure easier.

A small bruise or mild soreness around the blood test site is common and can last for a few days. Get medical care for your child if the discomfort gets worse or lasts longer. If you have questions about the CBC, speak with your doctor or the health professional doing the blood draw. Larger text size Large text size Regular text size. What Is a Blood Test? What Is a Complete Blood Count? A CBC measures: red blood cells, which deliver oxygen to the different parts of the body white blood cells, which help fight infections platelets, which help blood clot to stop bleeding Why Are CBCs Done?