Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier
WebMD

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine
WebMD

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion
    WebMD

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community
    WebMD

    Community

    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

HIV & AIDS Health Center

Font Size
A
A
A

HIV (Human Immunodeficiency Virus) Infection - Topic Overview

HIV (human immunodeficiency virus) is a virus that attacks the immune system, the body's natural defense system. Without a strong immune system, the body has trouble fighting off disease. Both the virus and the infection it causes are called HIV.

White blood cells are an important part of the immune system. HIV infects and destroys certain white blood cells called CD4+ cells. If too many CD4+ cells are destroyed, the body can no longer defend itself against infection.

The last stage of HIV infection is AIDS (acquired immunodeficiency syndrome). People with AIDS have a low number of CD4+ cells and get infections or cancers that rarely occur in healthy people. These can be deadly.

But having HIV doesn't mean you have AIDS. Even without treatment, it takes a long time for HIV to progress to AIDS—usually 10 to 12 years.

When HIV is diagnosed before it becomes AIDS, medicines can slow or stop the damage to the immune system. If AIDS does develop, medicines can often help the immune system return to a healthier state.

With treatment, many people with HIV are able to live long and active lives.

There are two types of HIV:

  • HIV-1, which causes almost all the cases of AIDS worldwide
  • HIV-2, which causes an AIDS-like illness. HIV-2 infection is uncommon in North America.

HIV infection is caused by the human immunodeficiency virus. You can get HIV from contact with infected blood, semen, or vaginal fluids.

  • Most people get the virus by having unprotected sex with someone who has HIV.
  • Another common way of getting it is by sharing drug needles with someone who is infected with HIV.
  • The virus can also be passed from a mother to her baby during pregnancy, birth, or breast-feeding.

HIV doesn't survive well outside the body. So it can't be spread by casual contact like kissing or sharing drinking glasses with an infected person.

1 | 2 | 3 | 4
1 | 2 | 3 | 4
Next Article:

Today on WebMD

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