banner illustration

HIV Overview

Human immunodeficiency virus, or HIV, is a virus that attacks the body's infection-fighting immune system. Today's treatments help lower the amount of virus in the blood so people who are HIV-positive can live healthier lives.

In This Article
View All
In This Article

Human immunodeficiency virus, or HIV, is a virus that attacks the body's infection-fighting immune system. Today's treatments help lower the amount of virus in the blood so people who are HIV-positive can live healthier lives.

What Is It?

HIV is a virus that attacks your immune system, leaving you vulnerable to other infections and diseases. It's believed to have originated in chimpanzees in Africa, and then was passed to humans who hunted them for meat. Although humans may have been infected with HIV as early as the 1800s, it took decades to spread to the rest of the world. HIV is only known to have been in the U.S. since the 1970s.

Despite huge advances in research, there's still no cure for HIV. If left untreated, it can progress into AIDS (Acquired Immunodeficiency Syndrome), which can be fatal. But by taking HIV medicines every day that tamp down the amount of virus in your bloodstream, it's completely possible to live a normal, healthy life, without transmitting HIV to your sex partners.


HIV has three stages.

When you're first infected and your immune system attempts to fight back, you're in what's called Stage 1, the "acute infection" stage. During this time, you have a high viral load (aka the amount of HIV in your bloodstream) and are extremely contagious.

As the virus advances, it spreads throughout your body, but at lower levels than it did at the beginning, although you can still infect others. This is Stage 2, or "chronic HIV infection." This can last over a decade. Without any treatment, HIV will eventually begin to multiply throughout your body again, increasing your viral load. If HIV progresses to Stage 3 (AIDS), the virus begins to significantly break down your immune system, leaving you vulnerable to a host of different illnesses.

People with AIDS have an extremely high viral load and are very contagious. The life expectancy for people diagnosed with AIDS is 3 years, but most HIV-positive people in the U.S. don't advance to this stage.


Not everyone will have the exact same symptoms, but generally speaking, here's what people who have HIV can experience.

Stage 1 (Acute HIV infection)

Two to four weeks after first being infected with HIV, you could have flu-like symptoms such as:

These symptoms may last a few days or they could linger for a few weeks. Some people don't have any signs at all.

Stage 2 (Chronic HIV infection)

It's common to not have any symptoms as HIV progresses.

Stage 3 (AIDS) During late-stage HIV, it's common for people to have:

  • Rapid weight loss
  • Fever that comes and goes
  • Intense night sweats
  • Extreme fatigue
  • Swollen lymph nodes in the armpits, neck, or groin area
  • Prolonged diarrhea
  • Sores in the mouth, genitals, or anus
  • Pneumonia
  • Discolored skin
  • Memory loss
  • Depression


HIV is spread through infected blood, semen, or vaginal secretions entering your body.

That means it can be spread through:

Vaginal sex: Most women who get HIV are infected this way.

Anal sex: This type of sex has the highest risk of HIV infection, especially if you're receiving (on the bottom).

Sharing needles and syringes: When you share drug paraphernalia, you come into contact with other people's blood.

Pregnancy, childbirth, and breastfeeding: This is the most common way that kids get HIV.

People of all ages, races, and sexual orientations can get HIV, but you're at higher risk if you:

  • Have unprotected sex (sex without a barrier method such as a condom)
  • Have multiple sex partners
  • Use injectable drugs
  • Have a sexually transmitted infection (STIs can cause genital sores that make it easier for HIV to infect you)

It's also important to know all the ways that you can't get HIV. For instance, you cannot get infected by:


Three different tests can check for HIV, including:

Antigen/antibody test: Using a blood sample from your finger or vein, this test looks for antibodies that your immune system has made to try to fight off HIV. It can also detect unique parts of the virus called antigens. This type of test is the most common way to test for HIV.

Antibody test: This type of test only looks for antibodies. If you use a rapid self-test that checks your saliva and gives you results in 20 minutes, you're using this kind.

Nucleic acid test (NAT): Although this type of blood test can see if you have HIV and how much of the virus is in your blood, it's expensive, so not widely used.

Whatever test you take, if the result is negative and you haven't had any possible exposure within the past 3 months, it's safe to assume that you don't have HIV. If your test is positive, it's important to talk to your doctor ASAP. They can do a follow-up test to confirm the result.


Once you have HIV, you have it for life — as of yet, there's still no cure. But thanks to plenty of new, effective medications, it's possible to live a normal, healthy life with HIV. If you regularly take your prescribed medicines and see your doctor, HIV can be kept from developing into AIDS.

Antiretroviral therapy (ART) is a type of medication that reduces the amount of HIV in your blood. Once you have an undetectable amount of the virus, there's virtually no risk that you'll transmit HIV to someone else through sex or to your baby, if you're pregnant. (You may still be able to pass it on through breastfeeding, though.) ART has the most benefits when you start it as soon as possible after you're infected with HIV.

It's also important to take it exactly as prescribed. — even after your viral load goes down, and even if you don't have any symptoms. Missing a dose here and there gives HIV a chance to spread throughout your body and weaken your immune system.


Despite the progress that's been made in HIV treatment, it's still a serious condition you want to avoid at all costs. Some ways you can stay safe:

Use condoms: They're the only form of birth control that can protect you from HIV and other sexually transmitted infections.

Get tested: And not just for HIV, but for all sexually transmitted infections (STIs). Having an STI raises your risk of getting infected with HIV. Ask your partner to get tested, too.

Think about limiting your sex partners: Your risk for HIV goes up with your number of partners.

Skip the douche: "Washing out" your vagina removes good bacteria that can help prevent an infection.

Don't share needles and syringes: Only use sterile drug equipment, and talk to your doctor, therapist, or someone else you trust about ways you can quit using drugs. Substance use can throw off your decision-making and steer you into other activities that may raise your risk of HIV.

The more of these tips you follow, the lower your risk of HIV will be.

To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter

Was this page helpful?
Related Articles