The performance of routine blood tests in the acute phase of HIV is not specific, because HIV is a virus, and most other viral infections cause routine blood tests, so it is not possible to determine the presence or absence of HIV infection by the performance of routine blood tests. Other routine blood indicators usually do not change, such as red blood cell count and hemoglobin, which may not be different from what the patient had before. Therefore, if HIV infection is suspected, the best way to confirm the diagnosis of HIV infection is to test for HIV antibodies and HIV-p24 antigen or HIV-RNA, which is HIV nucleic acid.