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　　Our reporter Fu Lili

　　June 14th is World Blood Donor Day. Blood donation is a kind of public welfare behavior. If everyone can give a love, it will save many lives.

　　But when it comes to blood donation, many people shake their heads. Why is such a good thing always rejected by people? This is because people have doubts and misunderstandings about whether blood donation affects their health, which leads to a low blood donation rate in China. Today, we will take you to recognize these misunderstandings, dispel your concerns with science, and give you the courage to love.

　　Rumor has it that donating blood will make people lose their strength.

　　In life, we often hear the saying that blood is the essence of the human body, and we can’t donate blood easily. Once we donate blood, we will be greatly weakened.

　　"This may be related to our traditional understanding. In fact, the blood of the human body has a certain self-renewal ability, so the blood is spitting out the old and absorbing the new all the time, and the regulating function of the human body can quickly replenish the lost blood, so it will not cause blood deficiency after blood donation, and it will not hurt the vitality." On June 9th, Rebecca, director of the blood transfusion department of Henan Cancer Hospital, said in an interview with a reporter from Science and Technology Daily.

　　Rebecca introduced that the total blood volume of an adult accounts for about 7% of the body weight & mdash; 8%, the total blood volume of a person weighing 60 kg is about 4800 ml, of which 80% of the blood participates in the peripheral circulation, and 20% of the blood is stored in the liver and spleen. A person donates blood 200— 400 ml, accounting for only 5% of the total blood volume & mdash; 10%, after blood donation, the blood stored in the liver and spleen will be mobilized to ensure that the blood volume involved in circulation will not decrease. Science has proved that a healthy person loses 10% blood at a time, which is within the range that the body can bear and will not cause discomfort.

　　"The water and inorganic substances lost after blood donation will be replenished in one to two hours; Plasma protein is synthesized by the liver and can be supplemented in a day or two; Platelets, white blood cells and red blood cells will soon return to their original levels. " Rebecca said.

　　Zhou Xueli, director of the Department of Blood Transfusion, Hematology Hospital of China Academy of Medical Sciences, also said that as long as blood donation is scientific according to regulations, it will not have any impact on the body. The person who donated the most blood in Guinness World Records is Australian James. In the past 60 years, he donated 1173 times, with an average of nearly 20 times a year. Now he is 81 years old and still healthy. It can be seen that blood donation does not affect health and longevity.

　　Myth 2: Blood donation can lead to anemia.

　　Anemia symptoms are dizziness, fatigue and pallor. Some people may think that blood donation will lead to anemia because of these situations after blood donation.

　　"In fact, this statement has no scientific basis." Rebecca said, first of all, everyone who participates in voluntary blood donation will be strictly screened according to the National Requirements for Health Examination of Blood Donors, and only those who pass the health screening can collect blood. Therefore, in the process of health screening before blood donation, it can also help the public to determine whether they have anemia and other diseases.

　　Secondly, our country stipulates that blood donation should not exceed 400 ml at a time, which only accounts for about 10% of the total blood of adults. Human blood has a powerful regeneration function, and the hematopoietic system will be restored and supplemented soon. Therefore, donating blood according to national regulations will not only cause anemia symptoms, but also stimulate the hematopoietic organs of the human body, which is beneficial to the regeneration of human blood cells.

　　In this regard, Zhou Xueli also believes that this kind of worry is superfluous. The life expectancy of red blood cells in human blood is about 120 days and that of white blood cells is about 7-mdash. After 14 days, the life span of platelets is about 7-mdash; Nine days. Human bone marrow has a powerful compensatory function. Under certain conditions, the hematopoietic function of bone marrow can be increased to 6-mdash; Eight times, a healthy person produces about 200 billion red blood cells and 120 billion platelets every day. The constant replacement of aging and new life not only maintains the balance of blood volume, but also ensures that blood is full of vitality. Therefore, participating in voluntary blood donation is not only anemia but also beneficial to health.

　　Myth 3: Blood donation will reduce immunity.

　　Many people are reluctant to donate blood, thinking that blood donation will lead to decreased immunity. Others said: "I used to be in good health, but I have been catching a cold since I donated blood. Blood donation has led to decreased immunity."

　　"At present, there is no relevant research and literature showing that blood donation will lead to decreased immunity." Rebecca said that the immune system as a human body.

　　Only when its own defense system works effectively can the human body better defend against diseases, environmental pollution and the invasion of toxins, and can it repair damaged organs and tissues and restore their original functions.

　　Rebecca introduced that the immune function of the body is mainly achieved through the activation of immune cells such as T, B and NK, the release of cytokines and the secretion of antibodies. T cells are the most important immune cells, and their activation restricts the whole specific immune response, including cellular immunity and humoral immunity. B cells are important immune cells in the immune system, which can differentiate plasma cells, synthesize and secrete immunoglobulin under the stimulation of antigens, and mainly perform humoral immunity of the body.

　　Blood donation 200— Eight indexes, such as white blood cells, platelets, total plasma protein, albumin, red blood cells, hemoglobin, hematocrit and serum iron, are usually 24 hours after blood donation — It can be restored to the level before blood donation in 3 months.

　　For those who donate platelets for free, their collection is carried out through a blood cell separator according to the different specific gravity of blood cell components. Because the specific gravity of platelets is 1.030— 1.035, and the specific gravity of lymphocytes is 1.050, which are relatively close, so the process of mechanical platelet collection will cause the loss of some lymphocytes. In the case of lymphopenia, T cells can increase in value by recognizing their own antigens and using cytokines that promote proliferation and survival, rebuild the steady state of T cells, maintain the functional integrity of each cell group, and rebuild the balance among various cell subsets. Therefore, donating blood will not reduce your immunity. After blood donation, bone marrow cells make blood, and people’s metabolism will increase, so to some extent, it can also improve their immunity.

　　Rumor 4: Blood donation can infect diseases.

　　The main reason why many people are unwilling to donate blood is that they are worried that they will catch infectious diseases when donating blood.

　　In this regard, Zhou Xueli said that the items contacted in the whole process of blood donation are disposable consumables, clean and sterile, and will not be reused, and there is no risk of infectious diseases.

　　Rebecca also believes that blood donation is very safe. Because the blood collection and supply workflow strictly implements the relevant provisions of the National Technical Operating Rules for Blood Stations, there are strict quality control links for key materials used in the blood collection process, such as blood bags, reagents, disinfectant, accessories, etc., and strict time and scope requirements for disinfection in the blood collection process. The blood collection materials used by blood donors are all disposable and destroyed after use, and there is no chance of getting infected. Therefore, it is very safe to participate in voluntary blood donation.

　　Myth 5: Blood donation will cause blood pressure instability.

　　Some people will have high or low blood pressure after donating blood, and they think that blood donation has caused blood pressure instability.

　　"Blood pressure instability is mostly caused by tension." Rebecca said that some blood donors may have symptoms of temporarily high or low blood pressure after donating blood, which is caused by mental stress during blood donation. Blood donation by healthy people will not cause blood pressure fluctuation, and it will not cause people to suffer from hypertension or hypotension.

　　In this regard, some experts said that some people have dizziness or even fainting when donating blood, which is actually a psychological reaction. Some people will feel nervous and afraid when they see the blood flowing, or people who are dizzy themselves may faint. Experts pointed out that people in this situation are not suitable for blood donation.