<P> In medicine, venipuncture or venepuncture is the process of obtaining intravenous access for the purpose of intravenous therapy or for blood sampling of venous blood . In healthcare, this procedure is performed by medical laboratory scientists, medical practitioners, some EMTs, paramedics, phlebotomists, dialysis technicians, and other nursing staff . In veterinary medicine, the procedure is performed by veterinarians and veterinary technicians . </P> <P> It is essential to follow a standard procedure for the collection of blood specimen to get the accurate laboratory results . Any kind of error in collection of blood or filing the test tubes may lead erroneous laboratory results . </P> <P> Venipuncture is one of the most routinely performed invasive procedures and is carried out for any of five reasons: </P> <Ol> <Li> to obtain blood for diagnostic purposes; </Li> <Li> to monitor levels of blood components (Lavery & Ingram 2005); </Li> <Li> to administer therapeutic treatments including medications, nutrition, or chemotherapy; </Li> <Li> to remove blood due to excess levels of iron or erythrocytes (red blood cells); or </Li> <Li> to collect blood for later uses, mainly transfusion either in the donor or in another person . </Li> </Ol>

Where do they put the needle for a blood test