There is no scientific basis for the claim that there are ten disadvantages of donating blood. In fact, blood donation in accordance with the regulations is generally not harmful to the organism, and only a small number of people can experience dizziness, nausea and other discomforts. In order to ensure the safety of blood donors and blood transfusion, China has stipulated that blood donors should be 18 to 55 years old, have a standard weight, no syphilis, AIDS and other infectious diseases, blood pressure, hemoglobin volume and so on need to meet the requirements, and each time you donate 200 to 400 ml of blood, with an interval of not less than half a year. For adults who meet the requirements, donating 200~400ml of blood will not affect the body too much, and it can also promote the hematopoietic function of bone marrow and the metabolism of blood, and the blood can usually return to normal after a period of time. A few donors may experience dizziness, nausea, fatigue and other discomforts during or after blood donation, which can be relieved after resting. If the symptoms are more serious, the donor should inform the doctor and reduce the amount of blood drawn or stop drawing blood according to the specific situation. Blood donation should be made at a regular blood donation organization, and a complete and strict examination should be carried out before blood donation. Those who do not meet the requirements are recommended to give up this blood donation, and after blood donation, they should take sufficient rest and nutrition to achieve the purpose of recovering as soon as possible.