A CBC is a significant test that determines if there are any increases or decreases in your blood cell counts; which includes red blood cells, white blood cells and platelets. Normal values vary depending on your age and your gender. Your lab report will tell you the normal value range for your age and gender.
A CBC can help diagnose a broad range of conditions, from anemia and infection to cancer, including but not limited to:
The complete blood count, or CBC, lists a number of many important values. Typically, it includes the following:
White blood cells (WBCs): These help to fight infections. If you have high WBC levels, it tells your doctor you have inflammation or infection somewhere in your body. If it’s low, you could be at risk for infection. The normal range is 4,500 to 10,000 cells per microliter (cells/mcL). (A microliter is a very tiny amount – one millionth of a liter).
RBC (red blood cell count): This is the number of red blood cells you have. These are important because they carry oxygen through your body. They also help filter carbon dioxide. If your RBC count is too low, you may have anemia or another condition. (If you have anemia, your blood has fewer red blood cells than normal.) The normal range for men is 5 million to 6 million cells/mcL; for women it’s 4 million to 5 million cells/mcL.
Hb or Hbg (hemoglobin): This is the protein in your blood that holds the oxygen. The normal range for men is 14 to 17 grams per deciliter (gm/dL); for women it’s 12 to 15 gm/dL.
Hct (hematocrit): How much of your blood is red blood cells. A low score on the range scale may be a sign that you have too little iron, the mineral that helps produce red blood cells. A high score could mean you’re dehydrated or have another condition. The normal range for men is between 41% and 50%. For women the range is between 36% and 44%.
MCV (mean corpuscular volume): This is the average size of your red blood cells. If they’re bigger than normal, your MCV score goes up. That could indicate low vitamin B12 or folate levels. If your red blood cells are smaller, you could have a type of anemia. A normal-range MCV score is 80 to 95.
Platelets: These play a role in clotting. This test measures the number of platelets in your blood. The normal range is 140,000 to 450,000 cells/mcL.
MCH (mean corpuscular hemoglobin): How much hemoglobin (a protein) is in your typical red blood cell. It carries oxygen to your organs and tissues. It also moves carbon dioxide from your organs and tissues back to your lungs.
MCHC (mean corpuscular hemoglobin concentration): This measures how concentrated the hemoglobin is in your typical red blood cell. It’s how densely packed the hemoglobin molecules are inside the cells.
RDW (red cell distribution width): How your much your red blood cells vary in size.
Reticulocyte Count: Your results help your doctor figure out what could be causing your anemia, if you have it.
MPV (mean platelet volume): The size of the platelets in your blood.
PDW (platelet distribution width): How much your platelets vary in size.
White Blood Cell Differential: There are five types of white blood cells. This test shows how many of each type you have: neutrophils, lymphocytes, monocytes, eosinophils, and basophils.
During a CBC, a lab technician will draw blood from a vein, typically from the inside of your elbow or from the back of your hand. The test will take only a few minutes. The technician:
A blood test can be slightly uncomfortable. When the needle punctures your skin, you might feel a prick or pinching sensation. Some people also feel faint or light-headed when they see blood. Afterwards, you may have minor bruising, but it will clear up within a few days.
Most CBC results are available within a few hours to a day after testing.
Test results will vary based on your blood cell counts. Here are the normal results for adults, but different labs may deliver slight variations:
|Blood component||Normal levels|
|red blood cell||In men: 4.32-5.72 million cells/mcL
In women: 3.90-5.03 million cells/mcL
|hemoglobin||In men: 135-175 grams/L
In women: 120-155 grams/L
|hematocrit||In men: 38.8-50.0 percent
In women: 34.9-44.5 percent
|white blood cell count||3,500 to 10,500 cells/mcL|
|platelet count||150,000 to 450,000/mcL|
A CBC is not a definitive diagnostic test. Blood cell counts that are too high or too low could signal a wide variety of conditions. Specialized tests are needed to diagnose a specific condition. Conditions that could cause an abnormal CBC and may require additional testing include:
If your CBC shows abnormal levels, your doctor may order another blood test to confirm results. They may also order other tests to help further evaluate your condition and confirm a diagnosis.