Routine blood tests do not always include HIV tests. Doctors can order HIV tests when they think patients are at risk for HIV infection.
HIV testing is usually done through a blood test, according to the Center for Disease Control. However, there are a few different kinds of tests for HIV. The most common is a laboratory antibodies test, which tests for the presence of HIV antibodies in the blood or oral fluid. This is usually conducted as a blood test, as antibody levels tend to be higher in the blood. The FDA approves two tests for home use: Home Access HIV-1 Test System and OraQuick In-home HIV test. The first involves a prick to the finger and the second involves a mouth swab. However, both of these tests require a laboratory test as a follow-up.
Because antibodies testing can only detect HIV 3 weeks after exposure, doctors can sometimes conduct an RNA test. This type of test looks for the presence of the virus in the blood instead of the antibodies. It can detect HIV as soon as it enters the bloodstream, which usually tales around 10 days. However, because they cost more than antibodies tests, doctors do not usually order them for HIV screening.
Routine blood work usually tests the levels of the blood's makeup, according to the National Heart, Lung, and Blood Institute. This includes a blood count of red blood cells, white blood cells, platelets, hemoglobin and hematocrit. Routine blood tests also measure blood glucose and cholesterol levels. Doctors may order HIV screening when they think a patient is at risk for HIV infection. However, they may not screen people they believe to be low risk, such as older patients, according to the UNC Chapel Hill School of Medicine. Patients should always be upfront with their doctors about things like sexual activity or drug use.