Generally speaking, people can regain normal physical strength on the same day of blood donation, and the red blood cells and hemoglobin can gradually return to the pre-donation level after 1 week. It is harmless to healthy people to donate about 200 to 400 milliliters of blood at a time. After donating blood, the human body will lose part of the red blood cells, platelets, white blood cells and plasma; after donating blood, it will stimulate the body’s hematopoietic function to strengthen, speed up the metabolism, and the blood stored in the human body will enter the circulation rapidly to replenish the lost volume of blood so that the body recovers. Generally speaking, some people may experience dizziness and other symptoms after blood donation, which can be gradually recovered after 30 minutes of rest. You can eat more vitamin-rich foods such as apples, bananas, grapes, etc., and more iron-containing foods such as pig’s liver and pig’s blood. Healthy citizens are encouraged to donate blood without compensation. After blood donation, they need to take sufficient rest, avoid strenuous exercise, supplement nutrition and adequate water, and maintain a good state of mind.