Complete Blood Count

A complete blood count (CBC) or full blood count (FBC) is a test requested by a doctor or other medical professional that gives information about the cells in a patient's blood. A CBC is also known as a "hemogram".

A complete blood count will normally include:

Red cells

• Total red blood cells - The number of red cells is given as an absolute number per litre.
• Hemoglobin - The amount of hemoglobin in the blood, expressed in grams per litre. (Low hemoglobin is called anemia.)
• Hematocrit or packed cell volume (PCV) - This is the fraction of whole blood volume that consists of red blood cells.
• Mean cell volume (MCV) - the average volume of the red cells. Anemia is classified as microcytic or macrocytic based on whether this value is above or below the expected normal range. Other conditions that can affect MCV include thalassemia and reticulocytosis.
• Mean cell hemoglobin (MCH) - the average amount of hemoglobin per red blood cell, in picograms.
• Mean cell hemoglobin concentration (MCHC) - the average concentration of hemoglobin in the cells.
• Red blood cell distribution width (RDW) - a measure of the variation of the RBC population

White cells
Total white blood cells - All the white cell types are given as a percentage and as an absolute number per litre.

A complete blood count with differential will also include:

• Neutrophil granulocytes - May indicate bacterial infection. May also be raised in acute viral infections.
• Lymphocytes - Higher with some viral infections such as glandular fever and. Also raised in lymphocytic leukemia, CLL.
• Monocytes - May be raised in bacterial infection
• Eosinophil granulocytes - Increased in parasitic infections.
• Basophil granulocytes
• A manual count will also give information about other cells that are not normally present in peripheral blood, but may be released in certain disease processes.

Platelets
Platelet numbers are given, as well as information about their size and the range of sizes in the blood.