<Tr> <Th> MedlinePlus </Th> <Td> 000431 </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> Blood transfusion is generally the process of receiving blood or blood products into one's circulation intravenously . Transfusions are used for various medical conditions to replace lost components of the blood . Early transfusions used whole blood, but modern medical practice commonly uses only components of the blood, such as red blood cells, white blood cells, plasma, clotting factors, and platelets . </P> <P> Historically, red blood cell transfusion was considered when the hemoglobin level fell below 100 g / L or hematocrit falls below 30% . Because each unit of blood given carries risks, a trigger level lower than that at 70 to 80 g / L is now usually used as it has been shown to have better patient outcomes . The administration of a single unit of blood is the standard for hospitalized people who are not bleeding, with this treatment then followed with re-assessment and consideration of symptoms and hemoglobin concentration . Patients with poor oxygen saturation may need more blood . The advisory caution to use blood transfusion only with more severe anemia is in part due to evidence that outcomes are worsened if larger amounts are given . One may consider transfusion for people with symptoms of cardiovascular disease such as chest pain or shortness of breath . In cases where patients have low levels of hemoglobin but are cardiovascularly stable, parenteral iron is a preferred option based on both efficacy and safety . Other blood products are given where appropriate, such as clotting deficiencies . </P>

Is the process of transferring blood from one person to another