What is a blood disorder? What are the manifestations? Hematologic diseases are also known as diseases of the hematopoietic system and include diseases that originate in the hematopoietic system (e.g., leukemia originates in the bone marrow tissue, etc.) and diseases that primarily involve the hematopoietic system (e.g., iron deficiency anemia, etc.). Hematologic disorders can be primary, most of which are congenital defects in hematopoiesis or malignant changes in bone marrow composition. They can also be secondary. Diseases of other systems such as nutritional deficiencies, metabolic abnormalities and physicochemical factors can also cause adverse reactions to the bone marrow system, and those with more pronounced changes in blood or bone marrow composition also fall under the category of hematologic disorders. There are many types of blood disorders, but the clinical manifestations have many similarities, mainly manifesting as fever, anemia, weakness, jaundice, blood oozing from the gums, purpura, etc. Physical examination may include enlarged liver and spleen, oral mucosal petechiae, joint hematoma, etc. When these symptoms appear clinically, one must not be careless and go to the hospital to first check the blood routine, and then consider whether a bone marrow aspiration test or other items are needed depending on the situation. How is blood produced? What are the functions of various blood cells? Blood is a viscous fluid that flows in the blood vessels and is divided into liquid components and tangible components. The liquid component refers to the plasma (50-60%) and the formed component refers to the blood cells (40-50%). The production of primitive blood cells starts from the fetal stage, and after birth the bone marrow becomes the only blood-forming organ. Blood cells mainly refer to red blood cells, white blood cells, platelets, and various immune cells. Red blood cells mainly transport oxygen and carbon dioxide and buffer acid and alkaline substances in the body. Leukocytes, on the other hand, are the first-line defenders of the inflammatory response, gathering and traveling to the site of inflammation for phagocytosis. In contrast, the body’s monocyte-macrophage system is relied upon for larger bacteria, parasites, etc. Platelets are involved in the processes of blood clotting, anticoagulation and fibrinolysis in the body. Each cell in the blood does its own job and works together to keep the blood system in a normal dynamic and stable state. What are the common tests for blood disorders? Can bone marrow aspiration and bone marrow biopsy hurt my body? Commonly used tests for hematological diseases include: blood routine, blood cell morphology examination, leukocyte classification, bone marrow cell analysis, blood cell chemical staining, chromosome karyotype examination, immunological examination, bone marrow pathology biopsy, related enzymatic examination, etc. Bone marrow aspiration is a common test for the diagnosis of blood diseases, and it is necessary for the diagnosis and differential diagnosis of many blood diseases, especially many malignant blood diseases. Bone marrow biopsy only takes bone marrow tissue of the size of a grain of rice, which also has no effect on the body.