”Sticky blood” is not a disease. The term “sticky blood” is a word that many people use, and literally, it is easy to associate it with thicker and stickier blood, which can slow the flow of blood and lead to blood clots, which can block blood vessels. Some popular science articles also emphasize that the elderly should drink a glass of water early in the morning to help dilute the blood and prevent cardiovascular disease. Others say that when summer arrives, blood tends to thicken, and so on. In short, blood thickening is not a good thing and should be solved in some way. However, this indicator, which attracts the attention of many middle-aged and elderly people, does not seem to be so important to doctors. They never consider “thick blood or not” as a criterion when judging a patient’s condition. Blood viscosity is the common language of the people, but it is a medical indicator of blood rheology, but there are many factors that influence this indicator, and its significance has to be determined in the context of other conditions of the patient. There are many people with so-called “thick blood”, but it may not necessarily lead to thrombosis, because thrombosis is the result of a combination of factors, if there is nothing wrong with the blood vessel itself, the blood vessel wall is smooth, then the blood viscosity is high, it may not block the blood vessel. However, if a person’s blood lipid, blood sugar and blood pressure are too high, it will damage the endothelium of blood vessels, make the inner membrane of blood vessel wall rough, form atherosclerosis, and make the blood vessels less elastic, which is the important factor leading to thrombosis and blocking blood vessels, so doctors are more concerned about the three risk factors of blood lipid, blood sugar and blood pressure. In addition, smoking and overweight (obesity) are also factors in the development of thrombotic diseases. When it comes to drinking water to “reduce blood viscosity”, it is important to understand only one statement objectively, as it is beneficial for the elderly to drink more water, which also facilitates the excretory function of the kidneys. But from the point of view of blood thinning, can only say that there is a role, not to solve the fundamental problem, do not have too much superstition in this. The most effective prevention method is still to take anti-platelet drugs such as aspirin. In order to eliminate the psychological impact of thick blood on people, it is also important to understand a few common statements. Some people say that blood is thicker in the summer, but the correct term should actually be blood concentration because there is a lot of sweating and water loss in the summer. In addition, physical examinations can easily show results of blood thickening, this is because general physical examinations require fasting, some people therefore even rarely drink water, and the result of fasting for more than ten hours causes an increase in blood viscosity.