Blood routine is a common clinical examination index, generally focusing on the items of white blood cells, red blood cells, platelets, hemoglobin and other values, if the blood system diseases need to be analyzed as a whole. Can simply analyze the four main indicators of blood routine: 1, the normal value of white blood cells is 4.0-10 × 10^9 / L, white blood cells below 4 × 110^9 / L clinically seen in patients after chemotherapy or immune deficient patients, white blood cells > 10 × 10^9 / L mostly seen in infectious diseases, red blood cells hemoglobin general comprehensive view, the normal value of cells 3.5-5×10^9 / L, hemoglobin 90-110 L, hemoglobin 90-110g/L need to pay attention to the slight difference between male and female erythrocyte hemoglobin indicators. 2, if the erythrocyte hemoglobin is lower than normal is mostly seen in anemia, higher than normal is mostly seen in diseases such as true erythrocytosis. 3, the normal value of platelets is 100-300×10^9/L, platelets below normal is mostly seen in thrombocytopenia prone to bleeding, higher than Normal is mostly seen in thrombotic diseases.