The answer is yes. Blood test is one of the most basic tests, which has the initial screening effect for many diseases, while the manifestation of hematologic diseases is mostly the obvious abnormality of bone marrow and peripheral blood cells, and brings a series of related clinical manifestations. Hematological diseases are a group of malignant diseases that seriously endanger human health, and are therefore also known as “blood cancers”, and at present there is no complete cure for many types of leukemia. Many types of leukemia do not yet have a cure. These diseases can cause great physical and mental harm to the patient, even death, and are expensive to treat. Although early diagnosis and prevention of blood disorders are not yet possible, certain types of blood disorders can be better controlled and treatment outcomes improved with early detection and treatment. Routine blood tests are the easiest way to initially detect such diseases. It is very meaningful to have regular check-ups with routine blood tests within six months or a year and compare the results of each test. Under normal non-disease conditions, the blood routine will remain relatively stable, only under normal physiological conditions, there is a certain fluctuation, for example, the white blood cells are lower in the quiet and resting state, and will increase after exercise; lower in the morning and higher in the afternoon; physical labor, hot and cold baths, sunlight or ultraviolet irradiation will cause the white blood cells to increase mildly; the cold and the heat can cause the white blood cells to increase markedly; and can even cause the white blood cells to rise to the normal condition after strenuous exercise. White blood cells can even be elevated to three to four times the normal level after strenuous exercise. Red blood cells and hemoglobin may decrease physiologically during the age of 6-7 years in children, and gradually increase with age, reaching a peak at the age of 25-30 years. In women, they may be affected by the menstrual cycle, endocrine factors, etc.; during pregnancy, there may be an increase in blood volume and blood dilution, resulting in a relative decrease in the number of red blood cells. Platelet counts are relatively stable, but may vary within a certain range due to daytime factors, climatic factors, diet, exercise and menstrual cycle, but such changes are not very significant. Therefore, it is important to pay attention to any non-physiologic changes in blood counts, such as significant increases and decreases. Various types of anemia are relatively easy to detect through routine blood tests, generally manifested by decreased hemoglobin and decreased red blood cells, accompanied by changes in red blood cell volume and morphology. Common disorders include iron deficiency anemia, megaloblastic anemia, chronic anemia, aplastic anemia, thalassemia, and some hemoglobinopathies. And the obvious increase and extreme decrease of leukocytes may be a manifestation of leukemia, some acute leukemia leukocyte count may be several times to dozens of times of normal people, and accompanied by the appearance of a variety of naïve cells in the peripheral blood, which should be paid special attention to, common diseases such as acute granulocytic leukemia, acute lymphoblastic leukemia, chronic granulocytic leukemia and so on. In adults, acute granulocytic leukemia is the most common, chronic granulocytic leukemia has a gradually increasing incidence with age, chronic lymphocytic leukemia develops more often after the age of 50, while in children, acute lymphocytic leukemia is the most common. Plasma cell leukemia is a malignant leukemia that is difficult to treat, and secondary plasma cell leukemia is particularly poorly treated and has a high mortality rate. Laboratory blood tests, when a significant increase in white blood cells is detected, a blood cell morphology test (or blood smear test) must be done. If naïve or abnormally shaped white blood cells are detected, it is important to contact a hematologist in a timely manner, and bone marrow tests and other tests are done to confirm the diagnosis, if necessary. Decreased platelet count should not be ignored either, when below 50 x 109/L there can be a tendency to bleed and when below 20 x 109/L there is a tendency to appear more severe. Thrombocytopenia can be seen in diseases such as idiopathic thrombocytopenic purpura and primary thrombocytopenic purpura. If there is a decrease in the number of red blood cells, white blood cells and platelets of three or two cell lines at the same time, it may be related to myelodysplastic syndromes, myelofibrosis or aplastic anemia. It seems that routine blood tests do have the role of a “diagnostic soldier” in the diagnosis and screening of hematologic diseases, which can detect abnormalities and diagnose hematologic diseases based on the preliminary blood changes through blood smear tests, bone marrow tests, special tests and experiments for hematologic diseases, and even more advanced techniques such as flow cytometry, PCR and molecular biology. More advanced and specialized techniques such as flow cytometry, PCR, and molecular biology can be used to diagnose and conduct in-depth research on these diseases.