Blood Transfusion

输血是通过静脉将血液或血液制品转移到血液循环中的过程。输血用于各种医疗条件，以替换血液中丢失的成分。早期输血使用全血，但现代医学实践通常只使用血液成分，如红细胞、白细胞、血浆、凝血因子和血小板。红细胞含有血红蛋白，通过提高体内的氧含量来增加铁的含量。输血时不常用白细胞，但白细胞是免疫系统的一部分，可以抵抗感染。血浆是血液的液态部分，起到缓冲作用，含有蛋白质和身体整体健康所需的重要物质。血小板参与血液凝结，防止身体出血。在这些成分被发现之前，医生认为血液是同质的。因此，许多患者死于血液不相容的转移。

Blood transfusion is the process of transferring 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.Red blood cells contain hemoglobin, and increase iron levels by improving the amount of oxygen found in the body. White blood cells are not commonly used during transfusion, but are part of the immune system, and fight infections. Plasma is the liquid part of the blood, which acts as a buffer, and contains proteins and important substances needed for the body’s overall health. Platelets are involved in blood clotting, preventing the body from bleeding. Before these components were known, doctors believed that blood was homogenous. Because of this, many patients died due to the transfer of incompatible blood.