In fact, it is not an independent disease, but a clinical syndrome. In fact, anemia is only the tip of the iceberg of many diseases in the human body. Finding the cause of the disease is the only way to treat it, just like appendicitis and ectopic pregnancy can cause abdominal pain, but there is no way to cure abdominal pain without finding the cause. Anemia, although not an independent disease, is one of the most common symptoms in daily life. People often say, “Doctor, I’m dizzy, can you see if I’m anemic?” I have low blood pressure, see if I am anemic?” And so on. To put it simply, anemia is a common clinical condition in which the volume of red blood cells in human peripheral blood is low, below the lower limit of the normal range. Due to the complexity of red blood cell volume measurement, hemoglobin (Hb) concentration is often used in clinical practice instead. Our hematologists believe that anemia is present at sea level in China with Hb<120g/L in adult males, Hb<110g/L in adult females (non-pregnant), and Hb<100g/L in pregnant women. After the diagnosis of anemia, it is necessary to further classify the degree of anemia: below the above criteria to 91 g/L is mild anemia, 61 - 90 g/L is moderate anemia, 31 - 60 g/L is severe anemia, and below 30 g/L is very Severe anemia. Hemoglobin is a component of red blood cells, which is often referred to as hemoglobin. Hemoglobin is an iron-containing protein that binds easily to oxygen where oxygen levels are high and separates easily from oxygen where oxygen levels are low. Because of this property of hemoglobin, the oxygen obtained from the respiratory tract is delivered to every corner of the body smoothly. If we compare blood vessels to the "traffic routes" of the human body, then red blood cells are the "buses" that carry oxygen molecules, and hemoglobin is the "seat" on the bus, which plays an important role in the oxygen supply of human The hemoglobin plays an important role in the oxygen supply of human tissues. Therefore, when the red blood cell content of the body decreases, the number of buses decreases, and the number of seats on the bus decreases accordingly, and the human tissues show a lack of oxygen. When the body tissues are not supplied with sufficient oxygen in anemia, a series of clinical manifestations will occur. Pale skin and mucous membranes, fatigue, weakness, dizziness, tinnitus, memory loss, and lack of concentration are early and common symptoms. Anemia can also include shortness of breath, tachycardia, loss of appetite, menstrual disorders, and loss of libido. In severe cases, heart failure may occur. However, with chronic mild anemia, the organism may adapt and the patient often does not have any uncomfortable symptoms and only finds out he has anemia when he visits the doctor for other diseases or during routine physical examination. Anemia is not an independent disease, and many diseases can manifest as anemia. Therefore, after anemia is detected by routine blood test, you should clarify the degree, type and cause of anemia through medical history, physical examination and further relevant tests such as bone marrow test, ultrasound, gastroscopy, etc., and then do the corresponding treatment, including removing the cause, treating the original disease, applying blood-raising drugs and blood transfusion, etc. Do not use drugs indiscriminately before the cause is clear. The causes of anemia are complex and can be broadly classified into three conditions: decreased erythropoiesis, excessive destruction of erythrocytes (hemolytic anemia), and excessive loss of erythrocytes (hemorrhagic anemia). (1) Erythropoietic anemia Why does the bone marrow, the organ of hematopoiesis, produce fewer red blood cells? It is easy to understand and analyze if the bone marrow is compared to a hematopoietic factory. The first one may be the lack of raw materials for hematopoiesis, which mainly includes iron, vitamin B12, folic acid, vitamin B6 and protein, etc. Common types include iron deficiency anemia and megaloblastic anemia; the second one may be the paralysis or shutdown of the hematopoietic factory itself, such as the destruction of bone marrow due to infection, poisoning, radiation, or occupation by other cells such as tumor cells, etc. Common types include aplastic anemia, myelodysplastic syndrome, leukemia, etc. The third possibility is that the "lubricant" that makes the factory run is insufficient, that is, the lack of factors regulating the production of red blood cells, such as erythropoietin reduction, etc. The common types are renal anemia, endocrine gland (such as pituitary gland, thyroid gland) Hypofunction, etc. (2) Excessive destruction of red blood cells (hemolytic anemia) Under normal circumstances, the life span of red blood cells is 120 days, and about 1% of senescent red blood cells are removed from the blood every day, while a corresponding number of new red blood cells are released from the bone marrow into the blood to maintain a constant number of red blood cells. When the life span of erythrocytes is shortened and destruction increases, although bone marrow hematopoiesis is enhanced, it is not enough to compensate for the loss of erythrocytes, and the resulting anemia is called hemolytic anemia. The common ones are hemolysis due to intrinsic defects of red blood cells, such as marine anemia, G6PD deficiency (sericosis), etc.; hemolysis due to abnormalities in the external environment of red blood cells, such as autoimmune hemolysis, neonatal hemolysis, transfusion-related hemolysis due to blood group discrepancies, etc. (3) Excessive red blood cell loss (hemorrhagic anemia) is divided into acute and chronic according to the rate of blood loss, and chronic hemorrhagic anemia is often combined with iron deficiency anemia. According to the etiology of blood loss, there are two categories: those caused by bleeding disorders (such as immune thrombocytopenia, hemophilia and severe liver disease) and those caused by non-bleeding disorders (such as trauma, tumors, tuberculosis, bronchiectasis, peptic ulcers, hemorrhoids and gynecological diseases). As can be seen, the clinical causes of anemia are complex, and the treatment methods differ according to the causes, which need to be carefully identified by doctors according to clinical manifestations and various auxiliary examinations. Therefore, if anemia symptoms appear, you should go to a specialist for further examination in a timely manner. Misuse of supplements will not only fail to cure the disease, but will probably delay it. It is also important to identify the cause of anemia after the nature of the anemia has been clarified, as often the diagnosis and treatment of the cause is more important.