What is HIV? What is AIDS?
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.
treatment, many people with HIV are able to live long and active lives.
There are two types of
- HIV-1, which causes almost all the cases of
- HIV-2, which causes
an AIDS-like illness. HIV-2 infection is uncommon in North America.
What causes HIV?
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
- 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
What are the symptoms?
HIV may not cause symptoms
early on. People who do have symptoms may mistake them for the
mono. Common early symptoms include:
- Muscle aches and joint
- Swollen glands (swollen lymph nodes).
- Skin rash.
Symptoms may appear from a few days to several weeks
after a person is first infected. The early symptoms usually go away within 2
to 3 weeks.
After the early symptoms go away, an infected person
may not have symptoms again for many years. After a certain
point, symptoms reappear and then remain. These symptoms usually
- Swollen lymph nodes.
- Weight loss.
How is HIV diagnosed?
A doctor may suspect HIV if symptoms last and no
other cause can be found.
have been exposed to HIV, your immune system will make antibodies to try to
destroy the virus. Doctors use tests to find these antibodies in urine, saliva, or blood.
If a test on urine or saliva shows that you are infected
with HIV, you will probably have a blood test to confirm the results.
Most doctors use two blood tests, called the ELISA and the Western blot. If the first ELISA is positive (meaning that HIV antibodies are found),
the blood sample is tested again. If the second test is positive, a Western blot will be done to be sure.
It may take as long as 6 months
for HIV antibodies to show up in your blood. If you think you have been
exposed to HIV but you test negative for it:
- Get tested again. Tests at 6, 12, and 24 weeks can be done to be sure you
are not infected.
- Meanwhile, take steps to prevent the spread of
the virus, in case you do have it.
You can get HIV testing in most
doctors' offices, public health clinics, hospitals, and Planned Parenthood
clinics. You can also buy a home HIV test kit in a drugstore or by mail order. Make sure it's one that is approved by the Food and Drug Administration (FDA). If a home test is positive, see a doctor to
have the result confirmed and to find out what to do next.
How is it treated?
The standard treatment for HIV
is a combination of medicines called antiretroviral therapy, or ART. Antiretroviral medicines slow the rate at which the virus multiplies.
Taking these medicines can reduce the amount of virus in your body and help you
Medical experts recommend that people begin treatment for HIV as soon as they know that they are infected.1, 2
monitor the HIV infection and its effect on your immune system, a doctor will
regularly do two tests:
- Viral load, which shows the amount of virus
in your blood.
- CD4+ cell count, which shows how well your immune system is
After you start treatment, it's important to take your medicines exactly
as directed by your doctor. When treatment doesn't work, it is often because
HIV has become
resistant to the medicine. This can happen if you
don't take your medicines correctly.
How can you prevent HIV?
HIV is often spread by people who don't know they have it. So it's always important to protect yourself and others by taking these steps:
- Practice safer sex. Use a condom every time
you have sex (including oral sex) until you are sure that you and your partner aren't infected with HIV or other sexually transmitted infection (STI).
- Don't have more than one sex partner at a
time. The safest sex is with one partner who has sex only with
- Talk to your partner before you have sex the first time. Find
out if he or she is at risk for HIV. Get tested together. Getting tested again at 6, 12, and 24 weeks after the first test can be done to be sure neither of you
is infected. Use condoms in the meantime.
- Don't drink a lot of alcohol
or use illegal drugs before sex. You might let down your guard and not practice
- Don't share personal items, such as toothbrushes or
- Never share needles or syringes with anyone.
You also can take antiretroviral medicine to help protect yourself from HIV infection. But to keep your risk low, you still need to practice safer sex even while you are taking the medicine.
Frequently Asked Questions