Key Facts
  • HIV and AIDS are not the same thing.
  • HIV is a virus that can lead to an AIDS diagnosis if untreated.
  • HIV is spread through unprotected sex and sharing needles.
  • There is no cure for HIV, but it can be treated.
  • Esta guía en Español
  • Young men's version of this guide


HIV (human immunodeficiency virus) is a virus that attacks the body’s immune system. If HIV is not treated, it can lead to AIDS (acquired immunodeficiency syndrome). Learning the basics about HIV can keep you healthy and prevent HIV transmission. HIV/AIDS can now be treated with medicine.  You can have HIV and not know it. According to the CDC, 1.2 million people are living in the United States. Nearly 13% of them don’t know they are living with HIV. There is currently no cure. Once people get HIV, they have it for life, BUT with proper medical care, HIV can be controlled. People with HIV who get effective HIV treatment can live long, healthy lives and protect their partners.

What are HIV and AIDS?

HIV stands for human immunodeficiency virus. It weakens a person’s immune system by destroying important cells that fight disease and infection. These white blood cells called T-cells and in your immune system and are what fights against infections to keep your body healthy. T-cells play a key role in keeping a person protected from infections. If your immune system is weakened, it can’t protect your body and you can easily get sick. If a person with HIV does not get medical care, HIV will attack the immune system and they will eventually develop AIDS. AIDS can allow different types of life-threatening infections and cancers to develop and can lead to death.

Who gets HIV/AIDS?

Anyone who has unprotected sex (without a condom) and/or shares needles or injection drug equipment with an infected person is at risk for getting the HIV virus. Also, babies can be born with the virus if their mother is infected and is not on treatment. Some groups of people in the United States are more likely to get HIV than others because of many factors, including their sex partners, their risk behaviors, and where they live.

Does everyone who has HIV get AIDS?

Not all people with HIV get AIDS. However, if a person’s T-cell numbers drop and the amount of virus in the blood stream rises (viral load), the immune system can become too weak to fight off infections, and they are considered to have AIDS. It is then possible to get sick with diseases that do not usually affect other people. One of these diseases is Kaposi Sarcoma (KS), a rare type of cancer. Another is a type of pneumonia called Pneumocystis Pneumonia (PCP). These diseases can be treated, and a person’s T-Cells and viral load can return to healthier levels with the right types of medication, although the AIDS diagnosis stays with them even when healthy.

How is HIV spread?

HIV is found in and can be passed from an infected person to another person through blood, semen, vaginal fluid, and breast milk. People can most easily be exposed to HIV by having anal, vaginal sex without using a condom or by using a condom incorrectly. This is especially possible when 1 partner has an open sore or irritation (like the sores we can get from sexually transmitted infections like herpes or syphilis) or through small tears in the vagina and anus from vaginal or anal intercourse. The chance that an HIV-negative person will get HIV from oral sex with an HIV-positive partner is extremely low. Mothers living with HIV can pass the virus to their babies if they are not taking their medications or if they are not virally suppressed (virally suppressed meaning we can’t detect the virus in their blood), during pregnancy and birth and also during breastfeeding. HIV is also spread when sharing needles or injection drug equipment with an infected person. Your risk for getting HIV is very high if you use needles or works after someone with HIV has used them.

If you have another you are more likely to get or transmit HIV to others. Common STIs include gonorrhea, chlamydia, syphilis, trichomonas, human papillomavirus (HPV), genital herpes, and hepatitis. The only way to know for sure if you have an STI is to get tested. If you’re sexually active, you and your partners should get tested for STIs (including HIV if you’re HIV-negative) regularly, even if you don’t have symptoms.

If you are HIV-negative but have an STI, you are about 3 times as likely to get HIV if you have unprotected sex with someone who has HIV. If you are living with HIV and also have another STI, you are about 3 times as likely as other people with HIV to transmit HIV through sexual contact. This seems to happen because there is an increased concentration of HIV in the semen and genital fluids in individuals living with HIV, who also have another STI.

HIV can only be spread through intimate contact with one or more of the fluids discussed above.

HIV is not spread through touching, hugging, or shaking hands with an infected person. HIV is not spread through saliva. It is not spread by coughing, sneezing, sharing glasses and dishes, touching toilets or doorknobs. Pets and biting insects, like mosquitoes, do not spread the virus. Donating blood does not spread HIV either. This is because a new needle is used for each donor, so you never come in contact with another person’s blood.

What are the symptoms of HIV/AIDS?

Some people may get an illness within 6 weeks of HIV infection. When people with HIV don’t get treatment, they typically progress through three stages. But HIV medicine can slow or prevent progression of the disease. With new medicines and treatments, progression to Stage 3 is less common today than in the early days of HIV. This early period in the infection may come with some of the following symptoms:

  • Fever
  • Headache
  • Swollen glands
  • Tiredness
  • Aching joints and muscles
  • Sore throat
  • Fatigue
  • Mouth Ulcers
  • Swollen lymph nodes

What are the stages of HIV?

When people with HIV don’t get treatment, they typically progress through three stages. But HIV medicine can slow or prevent progression of the disease. With new medicines and treatments, progression to Stage 3 is less common today than in the early days of HIV.

Stage 1: Acute HIV Infection

  • People have a large amount of HIV in their blood. They are very contagious.
  • Some people have flu-like symptoms. This is the body’s natural response to infection.
  • But some people may not feel sick right away or at all.
  • If you have flu-like symptoms and think you may have been exposed to HIV, seek medical care and ask for a test to diagnose acute infection.
  • Only antigen/antibody tests or nucleic acid tests (NATs) can diagnose acute infection.

Stage 2: Chronic HIV Infection

  • This stage is also called asymptomatic HIV infection or clinical latency.
  • HIV is still active but reproduces at very low levels.
  • People may not have any symptoms or get sick during this phase.
  • Without taking HIV medicine, this period may last a decade or longer, but some may progress faster.
  • People can transmit HIV in this phase.
  • At the end of this phase, the amount of HIV in the blood (called viral load) goes up and the CD4 cell count goes down. The person may have symptoms as the virus levels increase in the body, and the person moves into Stage 3.
  • People who take HIV medicine as prescribed may never move into Stage 3.

Stage 3: Acquired Immunodeficiency Syndrome (AIDS)

  • The most severe phase of HIV infection.
  • People with AIDS have such badly damaged immune systems that they get an increasing number of severe illnesses, called opportunistic infections.
  • People receive an AIDS diagnosis when their CD4 cell count drops below 200 cells/mm, or if they develop certain opportunistic infections.
  • People with AIDS can have a high viral load and be very infectious.
  • Without treatment, people with AIDS typically survive about three years.

What should I do if I think I have HIV or AIDS?

If you think you are infected with HIV or have been exposed to someone whom you suspect or know to be living with HIV, or if you have symptoms, get tested and make an appointment with your health care provider right away. The earlier you get tested the sooner you can start medicine to control the virus. Getting treated early can slow down the progress of the HIV infection and may even prevent you from getting AIDS. Knowing if you are living with HIV or not will help you make decisions about protecting yourself and others.

How is HIV diagnosed?

HIV is diagnosed using three different types of tests available: nucleic acid tests (NAT), antigen/antibody tests, and antibody tests. HIV tests are typically performed on blood or oral fluid. The tests may also be performed on urine.

  • NAT looks for the actual virus in the blood and involves drawing blood from a vein. The test can either tell if a person has HIV or tell how much virus is present in the blood (known as an HIV viral load test). While a NAT can detect HIV sooner than other types of tests, this test is very expensive and not routinely used for screening individuals unless they recently had a high-risk exposure (if your partner is living with HIV or after a sexual assault) or a possible exposure and have early symptoms of HIV infection. NAT and antigen/antibody) require blood to be drawn from your vein into a tube and then that blood is sent to a laboratory for testing. The results may take several days to be available. A nucleic acid test (NAT) can usually tell you if you have HIV infection 10 to 33 days after an exposure.
  • An antigen/antibody test looks for both HIV antibodies and antigens. Antibodies are produced by your immune system when you’re exposed to viruses like HIV. Antigens are foreign substances that cause your immune system to activate. If you have HIV, an antigen called p24 is produced even before antibodies develop. This test involves drawing blood from a vein. There is also a rapid antigen/antibody test available that is done with a finger prick. The rapid antigen/antibody test done with a finger prick and takes 30 minutes or less for a result to appear. An antigen/antibody test performed by a laboratory on blood from a vein can usually detect HIV infection 18 to 45 days after an exposure. Antigen/ antibody tests done with blood from a finger prick can take longer to detect HIV (18 to 90 days after an exposure).  All rapid tests done that show a positive or reactive result need to be confirmed by sending another sample to the lab.  There are circumstances that can give you a false positive result (for example pregnancy, or recent infection with herpes and there are some medical conditions that can cause you to have a false positive result)
  • HIV antibody tests only look for antibodies to HIV in your blood or oral fluid. In general, antibody tests that use blood from a vein can detect HIV sooner after infection than tests done with blood from a finger prick or with oral fluid. Most rapid tests and the only currently approved HIV self-test are antibody tests. The oral fluid antibody self-test provides results within 20 minute. Antibody tests can take 23 to 90 days to detect HIV infection after an exposure. Again there are medical conditions that can give you a false positive.

Talk to your health care provider about what type of HIV test is right for you.

What does a “false negative” test result mean?

If you are tested too soon after being exposed to HIV, it is possible that you can get a “false negative”. This is because it can take between 2 and 12 weeks after infection for the HIV test to become positive, depending on the type of test used. It is usually recommended that you have the test repeated after 3 months to make sure that you are truly negative.

What about sex partners?

If you find out that you are living with HIV, you can help prevent the spread of HIV by telling anyone that you have had sex with or anyone you have ever shared needles with (since your last negative HIV test). Your partner(s) can also start on a medication which is taken once a day to prevent HIV.  It is called pre-exposure prophylaxis (PrEP).  When this medication is taken consistently, PrEP is 99% effective in preventing HIV from sex when taken daily. Among people who inject drugs, PrEP reduces the risk of getting HIV by at least 74% when taken daily at the same time. Taking HIV medicine as prescribed can make your viral load very low. This is called viral suppression—usually defined as having less than 200 copies of HIV per milliliter of blood.

HIV medicine can make your viral load so low that a test can’t detect it. This is called an undetectable viral load. Getting and keeping an undetectable viral load is the best thing you can do to stay healthy. Also, if your viral load stays undetectable, you have effectively no risk of transmitting HIV to an HIV-negative sex partner. If you notify your partner right away about your status, your partner can get tested and treated or started on PrEP as soon as possible. If you feel that you can’t tell your partner or would like help telling them, ask your health care provider for advice. They can let people know confidentially that they may have been exposed.

How is HIV/AIDS treated?

Right now, there is no cure for HIV infection or AIDS. It is a chronic illness and the virus stays in your body for your lifetime. The virus has been treated with a combination of different drugs which, when taken together at the same time every day without missing doses, work to keep the virus quiet so the immune system can stay strong. Following your doctor’s treatment plan is extremely important. Your health care provider may also tell you to eat healthy foods, exercise, and lower any stress in your life. All these factors work together to keep you healthy and feeling good.

If I already have HIV, can I get another kind of HIV?

This is called HIV superinfection. HIV superinfection is when a person with HIV gets infected with another strain of the virus. The new strain of HIV can replace the original strain or remain along with the original strain.

How can I protect myself from getting HIV?

  • The best way to avoid getting HIV is not to have sex and not share needles. If you do decide to have sex, you should always practice safe sex, using a new condom each time. Condoms come in different textures, sizes, colors and even flavors so there are plenty of options to try out.
  • Limit the number of sexual partners that you have. If you and your partner are sexually active, you can make sure that both of you are tested and treated for other STIs (if necessary).
  • Make sure you use a condom correctly every time you have vaginal, anal, or oral sex. Using condoms, internal (female) condoms, finger cots and dental dams when having sex lowers your risk for getting HIV and other STIs. Be sure to check that the condom or other product you’re using is not expired, punctured, or otherwise damaged – if it is, throw it away and use a fresh one. It’s a good idea to talk to your health care provider about testing/prevention even if you use condoms every time you have sex.
  • Use sterile needles if you plan on getting a tattoo or body piercing or if you use IV drugs. This really does lower your risk of getting HIV. Don’t use anything that pierces your skin unless you are sure it has been fully sterilized. In Massachusetts and some other states, people who are 18 or older and use injection drugs can go to local needle exchange to get clean syringes and other supplies so they do not have to share or reuse their equipment.
  • Don’t share personal items such as razors and toothbrushes. These items could have blood on them which can carry the virus (if the blood is from someone who happens to be HIV+).
  • High risk individuals who frequently have unprotected sex and/or use intravenous drugs can take a pill to help prevent HIV. This is called pre-exposure prophylaxis or PrEP. If you fit this category, talk with your doctor about this.
  • PrEP may also be a great option for individuals in serodiscordinant relationships. A serodiscordinant relationship is when one partner is living with HIV, while the other is not. PrEP would be taken by the partner who is not living with HIV.
  • Get tested! You can make sure that both you and your partner get tested for HIV before you have sex. Many health care providers’ offices, hospitals, and clinics offer HIV testing at a low cost or for free. If your test is positive, you might feel scared – talking with your health care provider or HIV tester as soon as possible to learn about treatment is a good place to start. Early treatment improves a person’s health and prevents some of the damage to the immune system that untreated HIV can cause. There are also safe environments like support groups to find help working through your feelings and getting answers to your questions.

Content source: Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention