We are not new to blood transfusions, and we have all donated blood, that is, to some people who need it. Blood transfusion is a therapeutic measure, a supportive and compensatory therapy. The therapeutic function of blood transfusion is not only to replenish blood volume, maintain blood volume, raise blood pressure to fight against shock and prevent hemorrhagic shock, but also to supply red blood cells with oxygen-carrying capacity to correct acute hypoxia caused by the reduction of red blood cells or their oxygen-carrying capacity, and to replenish various coagulation factors to correct blood clotting disorders in some patients. Therefore, depending on the cause of the patient’s illness and the specific purpose of the transfusion therapy, different types of transfusions can be given, such as acute blood loss, which causes a drop in blood pressure; severe anemia, which is best transfused with concentrated red blood cell suspension; patients who suffer from large burns, mainly due to a decrease in plasma, which is best transfused with plasma or plasma substitutes; patients with certain bleeding disorders, which can be fed with concentrated platelet suspension or plasma containing coagulation factors For certain bleeding disorders, concentrated platelet suspension or plasma containing clotting factors can be given to enhance clotting ability to promote hemostasis. The blood components that are then transfused are obtained through non-remunerated blood donation. Blood is donated to save lives, and blood donation is promoted for blood safety. According to the World Health Organization, uncompensated blood donors who volunteer to give blood regularly are the basis for a safe and adequate blood supply. The metabolism of blood in the human body is quite vigorous, with a normal mature red blood cell production cycle of 29 days and an average life span of 120 days. A person weighing 50 kg donates 400 ml of whole blood at a time, which is 1/10 of the total amount of blood in the human body. 80% of the blood in the human body normally participates in normal circulation, while another 20% is stored in the liver, spleen and other tissues and organs, which will be replenished in time once a hemorrhage occurs somewhere in the body. Generally speaking, a normal person with a body weight of 50 kg can donate 200-400 ml of whole blood at one time, and the red blood cells in the donor’s body will recover to the original level in 5-10 days after donation. Therefore, blood donation in moderation will not affect health. Moreover, moderate blood donation can have the effects of reducing cardiovascular diseases, reducing tumors, and preventing and relieving hyperviscosity. According to International Cancer, the chance of developing cancer increases when the iron level in the body exceeds 10% of the normal value, and young women lose a certain amount of iron due to monthly menstrual blood loss, thus reducing the incidence of these diseases compared to men. In contrast, men who donate blood in moderation can adjust their body iron levels and prevent cancer.