A wide variety of medical tests done on samples of blood taken from a vein (venipuncture), to assess the health of the body and its major systems. Hematological tests look at aspects of the blood itself; among such tests are complete blood count (CBC) and thrombin time, which measures blood-clotting ability. Microbiological tests search for infectious organisms carried in the blood and for antibodies that may have formed to counteract them; often these tests take the form of attempting to grow a culture in the laboratory. Biochemical or blood chemistry tests examine the substances carried in the blood, such as sodium and other elements, vitamins, gases, and drugs. Using medical shorthand, doctors often refer to different groups of tests by the organ whose health is being examined (for example, kidney function tests) or by the information sought, such as blood gases or thyroid-stimulating hormone (T4,T3).
A series of laboratory studies of blood samples used to screen for or to diagnose diseases. Some tests require only a drop or two of blood, and the sample is usually taken from the tip of the finger. When the test requires a larger sample, it is normally taken by needle from a vein in the elbow or on the back of the hand; the blood is collected in a sterile syringe or vacuum tube. Blood tests are usually painless, and complications are minor and rare.
A laboratory test of a blood sample to analyse its chemical composition.
Any test designed to discover abnormalities in a sample of a person’s blood, such as the presence of alcohol, drugs, or bacteria, or to determine the blood group.
Removal of venous, capillary or arterial blood for haematological, microbiological or biochemical laboratory investigations.
A test to determine the chemical, physical, or serological characteristics of the blood or some portion of it.