CBC Test: Purpose, What It Measures, and Normal Results

CBC Test: Purpose, What It Measures, and Normal Results

A complete blood count (CBC) test is a common blood test that measures the cells in your blood. These cells include red blood cells, white blood cells, and platelets.

Purpose of a CBC Test

A CBC test is used to:

* Diagnose anemia, which is a condition in which your blood does not have enough red blood cells.

* Diagnose leukemia, which is a cancer of the white blood cells.

* Diagnose infections, such as bacterial or viral infections.

* Monitor blood loss due to injury or surgery.

* Evaluate your overall health.

What a CBC Test Measures

A CBC test measures the following:

* Red blood cell count: The number of red blood cells in your blood.

* Hemoglobin: The amount of hemoglobin in your red blood cells. Hemoglobin is a protein that carries oxygen to your cells.

* Hematocrit: The percentage of red blood cells in your blood.

* Mean corpuscular volume (MCV): The average size of your red blood cells.

* Mean corpuscular hemoglobin (MCH): The average amount of hemoglobin in your red blood cells.

* Mean corpuscular hemoglobin concentration (MCHC): The average concentration of hemoglobin in your red blood cells.

* Platelet count: The number of platelets in your blood. Platelets are cells that help your blood to clot.

* White blood cell count: The number of white blood cells in your blood. White blood cells are cells that help your body fight infection.

* Differential white blood cell count: The percentage of different types of white blood cells in your blood.

Normal Results for a CBC Test

The normal ranges for a CBC test can vary slightly from lab to lab. However, the following are the general normal ranges:

* Red blood cell count: Men: 4.5-6.2 million cells/µL; Women: 4.1-5.1 million cells/µL

* Hemoglobin: Men: 14-18 g/dL; Women: 12-16 g/dL

* Hematocrit: Men: 40%-54%; Women: 36%-48%

* MCV: 80-100 fL

* MCH: 27-32 pg

* MCHC: 32%-36%

* Platelet count: 150,000-450,000 cells/µL

* White blood cell count: 4,500-11,000 cells/µL

* Differential white blood cell count: Neutrophils: 55%-70%; Lymphocytes: 20%-40%; Monocytes: 5%-10%; Eosinophils: 1%-3%; Basophils: 0%-1%

Interpreting Your CBC Test Results

Your doctor will interpret your CBC test results in light of your symptoms and medical history. If your results are abnormal, your doctor may order additional tests to confirm the diagnosis.

Some possible causes of abnormal CBC test results include:

* Anemia: A low red blood cell count, hemoglobin level, or hematocrit.

* Leukemia: A high white blood cell count or an abnormal differential white blood cell count.

* Infection: A high white blood cell count or an abnormal differential white blood cell count.

* Blood loss: A low red blood cell count, hemoglobin level, or hematocrit.

* Other medical conditions: A variety of other medical conditions, such as kidney disease, liver disease, or thyroid problems, can also cause abnormal CBC test results.

If you have any questions about your CBC test results, talk to your doctor.