Before donating blood for the first time, care should be taken to meet the age requirement, i.e. 18-55 years old. Those who are too old and in good physical condition can apply for a renewal of the annual limit. In order to prevent the occurrence of health problems due to irregularities in the process of blood donation, you should go to a regular place to donate blood. In addition, first-time donors should pay attention to diet and rest: 1. Diet: Avoid fasting the night before and on the day of blood donation to prevent hypoglycemia during the donation process. You should maintain a light diet and avoid spicy foods such as chili peppers, greasy and stimulating foods such as barbecue and fatty meats, and foods with too much protein such as seafood to avoid protein denaturation and allergic reactions in the blood. Strenuous activities should also be avoided after blood donation to avoid adverse reactions such as dizziness; 3. Drugs: Drugs, especially anti-platelet forming drugs, should be avoided for some time before blood donation; 4. Diseases: If you have infectious diseases, or people carrying various pathogens, such as hepatitis B virus, syphilis spirochetes, HIV and other pathogens infected and carriers. In addition, patients with bleeding tendencies and coagulation disorders should not donate blood, such as leukemia, thalassemia, hemophilia, etc. Patients need to explain to the operator in advance to avoid accidents after donation; 5. Other: Female donors should also avoid the three days before and after their periods, and women in pregnancy and breastfeeding should avoid donating blood. You should wear loose clothing on the day of blood donation. You should inform the medical staff in advance in case of blood or needle sickness. Some of the blood taken during the donation process will not affect healthy people. After blood donation, you can take appropriate amounts of water, iron and other nutrients and ensure adequate rest to promote rapid recovery.