HIV Symptoms, Signs, and Diagnosis

What are HIV/AIDS symptoms and signs?

  • During the first few weeks of HIV infection, mononucleosis-like or flu-like symptoms may occur that include fever, body aches, headache, and rarely a brief rash that may not be noticed. Many people do not have any symptoms at all.
  • Around seven or eight years after HIV infection on average, the person may begin to feel unwell. Signs of HIV infection in both men and women include swollen lymph glands, loss of energy, loss of appetite, and loss of weight. The person begins to develop frequent infections, progressing to more unusual infections, as the immune system begins to fail.
  • After starting effective treatment for HIV, most people begin to feel much better within a few weeks. Within a few months, immune cells improve and may even normalize.
  • It is important to remember that many people can have HIV infection for many years and be infectious to others without knowing it or even being aware that they were ever at risk for HIV. One in six people with HIV infection is aware of it.

How is HIV/AIDS diagnosed?

Blood testing for HIV is performed by a laboratory. The blood test includes a screening test, followed by a confirmatory test (western blot) if the screen is positive. Oral swab testing requires a confirmatory blood test if it is positive. A positive HIV blood test means that the person is infected with HIV virus. Many labs now use an HIV test for antibody and antigen in the blood. The sensitivity of the HIV tests is over 90%, and it is very rare to miss HIV infection. However, there is a window period within a few weeks after infection where HIV blood tests may not pick up the infection (a false negative). In general, rapid tests may be more likely to miss early HIV infection than blood tests, and the antigen/antibody blood tests may pick up HIV infection as early as three weeks after infection. The oral swab HIV antibody test may take 20 minutes to one hour for results (it does not include a confirmatory test). The blood HIV antibody test may take only one hour for results, depending on the laboratory's schedule, plus one to two more days for the confirmatory test if it is positive. There are two home HIV tests: OraQuick In-Home HIV test (oral swab specimen) and the Home Access HIV-1 Test System (finger stick blood specimen). Both of these tests require follow-up confirmatory testing by a laboratory if the result is positive. A health care provider can order confirmatory HIV testing. The companies that sell the tests provide information and counseling on what to do next. Any home HIV test should be approved and validated by the Food and Drug Administration (FDA); unapproved tests are not verified to be reliable. Because of the window period (false negative test) that may occur in early infections, a negative HIV test should be repeated within three months to be sure it is negative.

Also available are RNA tests that can test for HIV directly at about 10 days post infection, even before antibodies develop.

Medically reviewed by Robert Cox, MD; American Board of Internal Medicine with subspecialty in Infectious Disease


Switzerland. World Health Organization. "HIV/AIDS." <>.

United States. Centers for Disease Control and Prevention. "HIV/AIDS." Mar. 9, 2017. <>.