There are many causes of anemia, and their pathogenesis is also different, mainly in the following aspects
1. Insufficiency of erythrocyte production. Many causes can affect bone marrow hematopoiesis, acute and chronic leukemia, multiple myeloma and other blood and blood tumor cells. Bone marrow infiltration destroys bone marrow structure, inhibits bone marrow hematopoietic function, and causes anemia; insufficient EPO secretion by the kidneys in chronic renal insufficiency , Causing renal anemia; chronic diseases such as tuberculosis, rheumatoid arthritis, etc. due to insufficient response of the bone marrow to EPO, also cause anemia, called chronic anemia. Myelodysplastic syndrome due to abnormal development of bone marrow hematopoietic stem cells, the occurrence of pathological hematopoiesis and hematopoietic failure, reduced dietary intake or malabsorption causes the lack of certain hematopoietic raw materials or hematopoietic cofactors, such as iron, folic acid or vitamin B12 deficiency can cause nutrition Sexual anemia.
2. Increased destruction of red blood cells The destruction of red blood cells is also called hemolysis. The direct rupture and dissolution of red blood cells in the blood vessels is called intravascular hemolysis; paroxysmal nocturnal hemoglobinuria (PNH), autoimmune hemolysis, glucose-6-phosphate dehydrogenation deficiency (G6PD deficiency) can all have acute intravascular hemolysis , A large amount of hemoglobin is released in a short time, and hemoglobinuria and hemolytic jaundice appear. Thalassemia, hereditary spherocytosis, due to congenital defects, red blood cells are easily swallowed by the spleen and liver endothelial cells, resulting in extravascular hemolysis. Extravascular hemolysis is slow, hemoglobinuria and jaundice are not obvious, and splenomegaly is common . Other red blood cell destruction factors include drugs, snake venom, chemical poisons, mechanical extrusion, high temperature and other physical factors
3. Hemorrhage. In cases of acute massive bleeding such as trauma, surgery, gastrointestinal bleeding, hemorrhagic anemia can result from a decrease in the total amount of red blood cells; menorrhagia, repeated gastrointestinal bleeding, hemorrhoid bleeding and other chronic blood loss, if every time The amount of bleeding is not much, and often does not cause hemorrhagic anemia, but due to long-term loss of iron eventually lead to iron deficiency anemia.