The reason for taking two blood tests for HIV is that the vast majority of hospitals in our country test for HIV by checking for HIV antibodies. If the antibody test is negative, it means that the patient is not infected with HIV. If the antibody test is positive, a confirmatory test should be performed to determine if the patient is infected with HIV. The confirmatory test involves checking the patient’s antibodies again by protein blotting, which requires another blood draw, so it is necessary to draw blood twice to check for HIV. If the confirmatory test is also positive, it is confirmed that the patient is infected with HIV. If the confirmatory test is negative, it means that the patient is not infected with HIV.