The resistance encountered by blood as it flows through the blood vessels is called blood flow resistance. As blood flows, it consumes energy due to friction, which is generally expressed as heat energy. This thermal energy cannot be converted into potential or kinetic energy of the blood, so the pressure of the blood gradually decreases as it flows through the blood vessels. In the case of turbulent flow, each mass in the blood constantly changes the direction of flow, so the energy consumed is more than in the case of laminar flow, and the resistance to blood flow is higher. Blood lipid stasis and increased blood viscosity lead to smaller inner diameter of blood vessels and increased resistance! The resistance encountered when fluid flows in the blood vessels is called blood flow resistance. Blood flow resistance is caused by the consumption of energy due to friction during blood flow, which is generally expressed as heat energy. This thermal energy cannot be converted into potential or kinetic energy of the blood, so the pressure of the blood gradually decreases as it flows through the blood vessels. In the case of turbulent flow, each mass in the blood constantly changes its direction of flow, so the energy consumed is more than in laminar flow, and the resistance to blood flow is higher. Blood rheology examination. The resistance to blood flow is proportional to the length of the vessel and the viscosity of the blood, and inversely proportional to the fourth power of the radius of the vessel. Since the length of a vessel varies very little, the resistance to blood flow is determined primarily by the caliber of the vessel and the viscosity of the blood. For an organ, if the blood viscosity is constant, the blood flow to the organ depends primarily on the caliber of the resistance vessel for that organ. Blood test: Blood test is the detection and analysis of the quantity and quality of the three systems of blood’s tangible components, namely red blood cells, white blood cells and platelets. These three systems, together with plasma, make up the blood, which flows constantly in the body’s circulatory system and participates in the body’s metabolism and every functional activity, so blood plays an important role in ensuring the body’s metabolism, functional regulation and the balance of the body’s internal and external environment. Pathological changes in any of the organic components of blood can affect tissues and organs throughout the body; conversely, lesions in tissues or organs can cause changes in blood components, thus hematological analysis and its results can be of great help in understanding the severity of diseases. Most hospitals use automated hematology analyzers to do routine blood tests (currently called hematology analysis). Only 0.1 ml (about two large drops of blood) of anticoagulated blood is used for each test, and more than 20 results can be tested and printed in as little as 30 seconds or one minute.