There are certain specificities in the blood routine of novel coronavirus infection. Early clinical studies found that the main changes in the blood routine of patients were the changes in leukocytes, with most of them showing a decrease in leukocytes and a decrease in the proportion and absolute value of lymphocytes, and the lower the value of lymphocytes indicated that the disease would be more serious. Other blood markers, such as red blood cells and platelets, have not been found to be associated with infection. Blood test is a very important laboratory test for diagnosis of new coronavirus infection, which is different from other bacterial and viral infections, and can give a preliminary judgment of new coronavirus infection. Source: Dr. Yurai