Hematologists are no stranger to such scenarios – outpatients holding their physical examination reports and saying to their doctors, “Doctor, the doctor at the physical examination center said I’m anemic and asked me to see a specialist, so you can prescribe some blood supplements for me.” It’s right to supplement what is lacking, but anemia is not as simple as taking some blood supplements. Doctors need to take a detailed medical history, conduct relevant physical examinations and, if necessary, perform some laboratory tests, and only after the cause of anemia is clearly identified, can they give the appropriate treatment. Most patients can understand and cooperate, but a few patients think that doctors are making a big deal out of it. So, is it really important to check the cause of anemia? Let’s take a look at a few real clinical cases below A. Other diseases behind anemia 1. A middle-aged female patient with routine blood results suggesting moderate anemia and small red blood cell volume asked about menstruation, which seemed to be related to chronic blood loss with heavy menstruation, but then asked the medical history more carefully and found frequent abdominal pain in the past six months, as well as changes in stool habits. After stool tests and further colonoscopy, it was found that the iron deficiency anemia was caused by chronic blood loss due to colon tumor. After the tumor was removed, the anemia was less likely to occur. Therefore, there may be a serious disease hidden behind the seemingly simple anemia. 2. An elderly male patient, very pale and weak, was supported by his family to enter the consultation room. Routine blood tests revealed severe anemia and a very large red blood cell volume, which was suspected to be megaloblastic anemia caused by vitamin B12 or folic acid deficiency. Three days later, the blood test confirmed the vitamin B12 deficiency. After 3 days of treatment the patient’s general condition had improved and he was able to walk to the hospital on his own. At this point, the doctor asked the patient to go for a gastroscopy, which the family refused to do because they said they had no stomach discomfort. After much persuasion and mobilization, the patient agreed to have a gastroscopy, which resulted in severe atrophic gastritis with intestinal metaplasia. At this point, the cause of the anemia was finally clarified, and it was the malabsorption of vitamin B12 due to gastric disease, which depleted the body’s reserve of vitamin B12 and led to severe nutritional anemia. Therefore, it is necessary to examine the cause of anemia, and we must not be afraid of trouble. 3.A middle-aged woman, anemic for more than 2 years, has not been clear about the cause in many hospitals, and the effect of various blood supplements is not good, the anemia is getting more and more serious, and her face and strength are getting worse. After a comprehensive examination, it was found that the kidney function was poor, the blood creatinine was elevated, and she had reached the uremic phase, and was diagnosed with renal anemia. After the combined treatment of erythropoietin therapy and nephrology, the anemia was completely corrected in 3 months. Clinically, we can see a few patients with uremia who have no obvious symptoms in the kidney itself, but have anemia as the first symptom. In addition, there are various other diseases that can cause anemia, such as hypothyroidism, liver disease, rheumatism, etc. Second, some anemia does not require treatment A young man who had just graduated from college and found a job in a multinational company was found to have a significant increase in the number of red blood cells, 1/3 more than normal, while the volume of red blood cells was small and there was a mild decrease in hemoglobin. When asked about his medical history, the young man usually had no symptoms and his studies and life were not affected. Because of the possibility of not passing the entry physical examination, the young man was very frustrated. After a series of careful examinations by the hematology department, it turned out to be an anemia called “hereditary spherocytosis”, which is mild and does not require treatment and generally does not affect life and work. After the hematologist issued a certificate, the young man was able to get a job at the company of his choice. Therefore, not all anemia needs to be treated, and it is important to find out the cause of what needs to be treated and what does not before making a decision. Third, anemia is not just a blood disease Anemia is not a disease, it is a symptom that includes many diseases, such as aplastic anemia with poor hematopoiesis, iron deficiency anemia and megaloblastic anemia caused by insufficient nutritional elements, hemolytic anemia with good bone marrow hematopoiesis but destroyed red blood cells, anemia of chronic diseases caused by other diseases, bone marrow metastasis of malignant tumors, leukemia, and many hereditary anemias, such as erythrocyte membrane abnormalities, erythrocyte enzyme defects, and abnormal hemoglobin peptide chains. All of them may show a decrease in the number of red blood cells or a decrease in the number of hemoglobin during routine blood tests, but only when the cause of anemia is found can we treat the cause with good results. In order to clarify the cause of anemia, the basic tests include: medical history, physical examination, complications, diet, medication history; blood routine and reticulocytes, peripheral blood smear; iron metabolism, fecal occult blood; vitamin B12 and folic acid; liver function, kidney function, thyroid function; serum erythropoietin level, etc. If these tests still do not clarify the diagnosis, further tests such as bone marrow smear, bone marrow biopsy, chromosome examination, flow cytometry, etc. may be required. If hereditary anemia is suspected, genetic mutation tests will also be performed, as well as tests on parents and siblings. Therefore, if you find anemia, you should not rush to use “blood supplements”, which may not only be ineffective, but also delay the diagnosis and timely treatment. The only solution is to go to a specialist to find out the cause of the disease. Establishing the cause of the disease is a specialized and complex matter. However, as long as we pay attention to the etiological diagnosis of anemia, most patients can have their causes identified and receive the appropriate treatment.