Donating blood is a most honorable thing to do. Not only does it save lives, but it is also good for your health. However, although blood donation is good, it should not be done too often. The Blood Donation Law of the People’s Republic of China stipulates that the age of blood donation is 18-55 years old, the interval between blood donations is six months or more, and the amount of blood donated each time is 200-400 ml. There is a medical basis for this provision in our blood donation law. It is not possible to donate more frequently, as this would defeat the positive meaning of blood donation. Some people suggest that donating more blood is good for improving blood viscosity, which is not based on science. Proper blood donation can restore blood in excess and also improve the body’s hematopoietic function. This is because after blood donation, blood will be diluted, blood flow will be accelerated, oxygen supply will be increased, people will feel relaxed and clear-headed, which may effectively reduce the risk of blood clots and cerebrovascular accidents and myocardial infarction and other diseases. However, blood viscosity is also affected by a combination of factors such as the amount of lipids in the blood and the rate of metabolism. There is no accurate data on how much or how long the effect of simple blood donation lasts. If more blood is donated, not only will it not improve blood stickiness, but it will also have a detrimental effect on the body. Blood stickiness can cause dizziness and weakness, irritability, insomnia, elevated blood pressure, and susceptibility to blood clots. It is important to pay attention to this and to see a doctor for a comprehensive blood test and symptomatic treatment. At the same time need to pay attention to the following points: First, to develop good habits, diet should not be too greasy, meat and vegetables with reasonable, if there are symptoms of thick blood, we should eat light, drink more water, appropriate exercise, but avoid intense exercise. Second, maintain a good state of mind, adjust the happy mood. Release stress, choose a suitable way to relieve stress, such as meditation, listening to songs, find friends to talk, etc., which also helps prevent subhealth. Third, low-fat diet, avoid excess, otherwise excess fat and sugar accumulation in the body, will make the blood become sticky. Proper exercise, such as walking 30 minutes a day, which will make the whole body blood flow, but do not forget to exercise after the appropriate time to replenish water. Fourth, replenish water, drink more water every day, do not wait until you are thirsty to drink water. This is generally controlled through a period of time is able to improve the problem of blood stickiness. You can’t rely on more blood donations in a single way. This is risky.