Blood test can detect diseases of the blood system and problems of the function of other organs and systems of the body. Through blood test, diseases of the blood system can be detected, such as anemia, granulocytopenia, hematocrit, low platelet function, aplastic anemia, low coagulation function, hypopoiesis, which can be detected through the blood test. The dysfunction of other organs in the body can also be detected through blood test, for example, biochemistry can detect liver function, kidney function, whether there is diabetes or not, whether the blood uric acid is high or not, and how the heart functions. Rheumatism can be detected by checking rheumatism series, immunity level can be detected by checking autoimmune series, and thyroid problems can be detected by checking thyroid series.