Skip to content

    HIV & AIDS Health Center

    Font Size

    HIV and AIDS: How They’re Different

    HIV and AIDS are related, but they’re not the same.

    HIV is a virus. It causes AIDS, the disease you can get after the virus has infected your body and weakened your immune system.

    Recommended Related to HIV/AIDS

    Actress Gloria Reuben: AIDS Activist

    Gloria Reuben first started grappling with HIV issues as part of her role on ER, as physician assistant Jeanie Boulet, one of the first openly HIV-positive characters on prime-time TV. But soon, the scripts began to take over her off-duty thoughts. “It follows you around wherever you go,” says Reuben, who was on the ER set until 1999. And when she accepted an invitation to a fundraiser from the late Elizabeth Glaser, she stepped into a new role as an AIDS activist. This past July, Reuben, who now...

    Read the Actress Gloria Reuben: AIDS Activist article > >

    Not everyone who has HIV will get AIDS, though.

    Many people with the virus don’t know they have it. There are nearly 50,000 new cases of it each year in the U.S.

    HIV: The Basics

    HIV stands for “human immunodeficiency virus.”

    “Immunodeficiency” means the systems that fight illnesses in your body either aren’t working or aren’t there.

    Your immune system has cells called CD4 or T cells that help keep you healthy. HIV attacks these cells. The virus copies itself over and over, and the number of CD4 cells in your body goes down. This makes it hard for your body to protect itself from germs.

    You can get HIV from direct contact with:

    Most commonly, the virus is passed from person to person by:

    • Sex
    • Sharing needles
    • Mother-to-baby infection during pregnancy

    People with HIV often say they feel like they have the worst flu of their life. Early symptoms include:

    AIDS: The Basics

    AIDS stands for “acquired immunodeficiency syndrome.” HIV can become this disease if it’s not treated.

    More than 1.2 million people in the U.S. have an HIV infection. Nearly 27,000 have AIDS. It's the third, and most advanced stage of the infection.

    When you have HIV, your doctor will watch the amount of the virus in your system. You may hear this amount called your “viral load.” Two things will tell your doctor if it has become AIDS:

    Your CD4 count. A healthy immune system has a CD4 count of 500 to 1,600. A person with AIDS has a CD4 count below 200.

    AIDS-defining infections. These can worsen your HIV. They’re called also called opportunistic infections. Viruses or bacteria that don’t usually make healthy people sick can cause them in someone with HIV.

    Today on WebMD

    How much do you know?
    contemplative man
    What to do now.
    Should you be tested?
    HIV under microscope
    What does it mean?
    HIV AIDS Screening
    man opening condom wrapper
    HIV AIDS Treatment
    Discrimination Stigma
    Treatment Side Effects
    grilled chicken and vegetables
    obese man standing on scale
    cold sore