Full Blood Count

A complete blood count (CBC) is a blood test used to evaluate your overall health and detect a wide range of disorders, including anemia, infection and leukemia. A complete blood count test measures several components and features of your blood, including: Red blood cells, which carry oxygen.

A complete blood count, or CBC, is an easy and very common test that screens for certain disorders that can affect your health. A CBC determines if there are any increases or decreases in your blood cell counts. 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.

A full blood count (FBC) is a very common clinical procedure and often the “starting point” for most medical investigations. An FBC not only tests for disorders and abnormalities of the blood but, as blood travels throughout the whole body, it can give an indication of disease present in other organs.
An FBC, as the name suggests, is used to obtain a count of the blood cells in the sample of blood taken. The counts from this small sample are used to estimate the levels of different blood cells within your body’s blood system.
Blood is made up from three main types of blood cell: red blood cells, white blood cells and platelets. The number of cells present, the size and proportions of these cells, and the haemoglobin level are measured in an FBC. Haemoglobin is the oxygen carrying component of red blood cells.

Your doctor may order a CBC as part of a routine check-up or if you have unexplained symptoms such as bleeding or bruising. A CBC can help your doctor do the following.

•  Evaluate your overall health. 
•  Diagnose a health problem. 
• Monitor a health problem. 
•  Monitor your treatment. 

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:

• Iron or other vitamin and mineral deficiencies
• Bleeding disorders
• Heart disease
• Autoimmune disorders
• Bone marrow problems
• Cancer
• Infection or inflammation 
• Reaction to medication

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.

For infants – In young infants, a nurse will typically sterilize the heel of the foot and use a small needle called a lancet to prick the area. The nurse will then gently squeeze the heel and collect a small amount of blood in a vial for 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: