Skip Navigation Bar
NIH MedlinePlus the Magazine, Trusted Health Information from the National Institutes of Health


Symptoms, Diagnosis, Prevention and Treatment


  • Most people who have become recently infected with HIV will not have any symptoms. They may, however, have a flu-like illness within a month or two after exposure to the virus, with fever, headache, tiredness, and enlarged lymph nodes (glands of the immune system easily felt in the neck and groin). These symptoms usually disappear within a week to a month and are often mistaken for those of other viral infections. During this period, people are very infectious, and HIV is present in large quantities in blood, semen, and vaginal fluids.
  • More severe HIV symptoms—such as profound and unexplained fatigue, rapid weight loss, frequent fevers, or profuse night sweats—may not appear for 10 years or more after HIV first enters the body in adults, or within two years in children born with HIV infection.


  • Your health-care provider can diagnose HIV by testing blood for the presence of antibodies (disease-fighting proteins) to HIV. It may take HIV antibodies as long as six months after infection to be produced in quantities large enough to show up in standard blood tests. For that reason, make sure to talk to your health-care provider about follow-up testing.


  • Because there is no cure or vaccine to prevent HIV, the only way people can prevent infection from the virus is to avoid high-risk behaviors putting them at risk of infection, such as having unprotected sex or sharing needles.
  • NIAID urges everyone ages 13 to 64 to get tested for HIV as part of their routine health care. Catching HIV in its early stages can make a lifesaving difference.


  • NIAID and other researchers have developed drugs to fight both HIV infection and its associated infections and cancers. In combination with early detection through HIV testing, available HIV therapies can greatly extend years and quality of life, and have resulted in a dramatic decrease in AIDS deaths in the U.S.

NIH Research to Results

The NIH is working to find new and effective ways to prevent HIV. Research is focused on:

  • Behavioral strategies designed to increase condom usage, delay sexual activity among young people, and reduce sexually transmitted infections, which can make people more susceptible to HIV infection.
  • Using HIV medicines that can treat HIV as a way to prevent infection among high-risk groups.
  • Microbicides—gels, creams, or foams—that women could use to protect themselves against HIV.
  • Developing a safe, effective vaccine against HIV infection.
  • Drug abuse intervention and treatment programs to prevent HIV transmission among injection drug users.
Read More "HIV/AIDS" Articles

HIV, AIDS, and the Future / The Nation's Top HIV/AIDS Researcher Discusses This Continuing Health Threat / HIV / AIDS: Symptoms, Diagnosis, Prevention and Treatment / An Unequal Burden

Summer 2009 Issue: Volume 4 Number 3 Pages 13 - 15