The functions of blood include the provision of nutrients and oxygen for the body’s metabolism, anti-inflammatory and hemostatic effects. 1. The functions of blood are related to the components in blood. There are mainly red blood cells, white blood cells and platelets, electrolytes (calcium, potassium, sodium, chloride, etc.), albumin and immunoglobulin in blood. Among them, hemoglobin in red blood cells combines with oxygen and transports oxygen to various tissues and organs for cellular metabolism. 2. Leukocytes in the blood include neutrophils, lymphocytes, monocytes, etc. These cells play an important role in the body’s immune defense system. When pathogens such as bacteria, viruses and mycoplasma invade the human body, leukocytes play an anti-inflammatory role and remove these pathogens. 3. Platelets in the blood mainly play the role of hemostasis, when the body bleeds, platelets will gather to the bleeding site to form a thrombus, so as to achieve hemostasis. 4. Albumin in the blood can be used as a carrier of drugs, iron, etc., and transport these components to all parts of the body to play a role. Immunoglobulin is related to the strength of immunity and plays an important role in anti-inflammatory effects. 5. Electrolytes, sugars, proteins, fats, etc. in the blood are nutrients that ensure cellular metabolism.