The human body has a complex system of blood circulation. Blood passes through all the parts of the body. Blood is responsible for transporting nutrition and oxygen to the parts of the body that need nourishment. It is also responsible for removing waste products and transporting carbon dioxide away from these parts of the body after the food has been used. Blood is essential for maintaining body temperature as well as for carrying out transport for important items like hormones and other chemicals that are useful around the body. Because of the various complex tasks performed by the blood, it is useful for medical diagnosis as well. The various components of the blood are found in different concentrations. There are normal ranges for these components that include red blood cells, white blood cells and many others. These normal ranges are used to indicate the normal functioning of the body.
A complete blood count test is a blood test where many of the vital components of a patient’s blood are measured. It is one of the basic medical tests that are used for general health checkups. It is also used across diseases and conditions because it is the most basic test to establish the status of an individual’s health. Thus a complete blood count test may be conducted for patients suffering from basic flu to life threatening cancers. A normal complete blood count test would check for red blood cell count, white blood cell count, hemoglobin, blood platelet count and many other basic health indicators. When the test involves a differential then it is known as complete blood count with differential. The differential test is the test of the white blood cells themselves. While a complete blood count only checks the quantity of white blood cells, the differential test checks exactly which white blood cells are present and counts their level. The five types of white blood cells found in human blood are neutrophils, basophils, eosinophils, monocytes and lymphocytes.
The test is conducted in a clinic or hospital. It involves the drawing of blood from a patient’s forearm using a needle. The blood is collected in a vial and sent to a laboratory for analysis. For a complete blood count with differential, only one sample of blood is required. The patient is allowed to return home immediately after the test unless he or she is admitted in a hospital in the first place.