Laboratory examination of the physical and chemical properties and components of a sample of blood. Analysis includes number of red and white blood cells (erythrocytes and leukocytes); red cell volume, sedimentation (settling) rate, and hemoglobin concentration; blood typing; cell shape and structure; hemoglobin and other protein structure; enzyme activity; and chemistry. Special tests detect substances characteristic of specific infections.
Learn more about blood analysis with a free trial on Britannica.com.
Blood tests are used to determine physiological and biochemical states such as disease, mineral content, drug effectiveness, and organ function. Although the term blood test is used, most routine tests (except for most haematology) are done on plasma or serum instead of blood cells.
For the majority of blood tests, blood is usually obtained from the patient's vein. However, other specialized blood tests, such as the Arterial blood gas, require blood extracted from an artery. Blood gas analysis of arterial blood is primarily used to monitor carbon dioxide and oxygen levels related to pulmonary function. But, it is also used to measure blood pH and bicarbonate levels for certain metabolic conditions.
|Urea||2.5||6.4||mmol/L||BUN - blood urea nitrogen|
|Creatinine - male||62||115||μmol/L|
|Creatinine - female||53||97||μmol/L|
|Creatinine - male||0.7||1.3||mg/dL|
|Creatinine - female||0.6||1.1||mg/dL|
|Glucose (fasting)||3.9||5.8||mmol/L||See also glycosylated hemoglobin|