HIV facts

What is HIV

• HIV stands for human immunodeficiency virus.
• HIV weakens your immune system and makes it harder for your body to fight infections.
• HIV and AIDS are not the same thing—HIV is the virus that can cause AIDS (Acquired Immune Deficiency Syndrome).
• Currently HIV infection is not curable, but medication and regular medical care can help you stay healthy and prevent spreading HIV.
• Some people are more likely to contract HIV than others, especially if they are having sex or injecting drugs with people who are more likely to have HIV themselves.

How HIV spreads

HIV is usually spread through genital fluids during vaginal and anal sex. HIV can also be transmitted from blood during sex and sharing needles or other injection-drug equipment. Women with HIV can pass HIV to their babies during pregnancy, childbirth, and breastfeeding if they are not on HIV medications.

HIV is not spread through saliva, sweat, tears, urine, feces (poop), or if someone’s blood or genital fluid comes into contact with skin that doesn’t have a cut or sore.

How to treat HIV

HIV medication keeps you healthy

• An HIV care provider prescribes medication that controls your viral load. Viral load means the amount of HIV activity in your body.
• Once you have controlled your viral load with HIV medication, your immune system can function normally. This keeps you healthy long-term.
• Your HIV care provider will continue to monitor your health and ensure that the medication is working, by making sure your viral load is undetectable. If an HIV medication ever stops working for you, your provider can help you find a different medication that will work for you.

HIV medication keeps your partner/s healthy

• Once you have had an undetectable viral load while taking HIV medication for at least 6 months, there is no longer any risk of HIV transmission when you have sex.
• We call this "Undetectable = Untransmittable," or "U=U".

Symptoms of HIV

Early symptoms

Most people do not have any symptoms during early HIV infection. This is why regular HIV testing is important if you are at increased risk of HIV infection.

Some people experience flu-like symptoms a few weeks after getting infected with HIV—which can include fever, extreme tiredness, sore throat, headache, swollen lymph nodes, and rash. These symptoms can take days or weeks to appear after you’ve been infected with HIV and are called “acute retroviral syndrome.” These symptoms will go away on their own even without HIV medications, but you will still have HIV.

Later symptoms

If HIV is not treated with medications, it can damage a certain part of your immune system called CD4 cells or T-cells. When your CD4 cell count goes down, it becomes easier to get illnesses such as pneumonia and other serious infections that your body would normally be able to fight off. These types of illnesses are called “opportunistic infections.” If someone with HIV has a CD4 count below 200 or is diagnosed with an opportunistic infection, they are said to have AIDS. It can take 2-10 years, or more, from the time someone gets HIV to the time they develop AIDS.

How to get tested for HIV

No test is good enough to detect if you were infected with HIV until about 11 days after you were exposed. This time from when you are infected with HIV until a test result is positive is called the “window period.” If you are diagnosed with HIV before antibodies develop, it is known as “acute infection.”

It is recommended that everyone get at least 1 HIV test in their lifetime. Some people with certain risk factors should get tested more often.

There are several types of HIV tests currently available:

Rapid HIV test

• Looks for the antibodies that your body makes in response to HIV
• Detects HIV starting 4 weeks to 3 months after you were exposed, depending on the specific type of rapid test used
• A fingerstick blood test or oral swab test
• Results are available within 20-30 minutes

HIV Antigen/Antibody test

• Looks for both virus particles and the antibodies your body makes in response to HIV
• Detects HIV starting about 2 weeks after you were exposed
• Blood test
• Results are available in 5-7 business days

HIV viral load test

• Looks for HIV virus in your blood
• Detects HIV starting about 11 days after you were exposed
• Blood test
• Results are available in 5-10 business days

How to avoid getting HIV

• PrEP is medication taken before a possible exposure to HIV. It is a highly effective way to reduce the risk of HIV infection through sex or sharing needles. PrEP needs to be taken on an ongoing basis if you have a continued risk of exposure to HIV.
• PEP is medication that can prevent HIV infection after you are exposed. It should be started within 72 hours of a possible exposure to HIV so it is important to come to the clinic quickly if you think you could have been exposed. You’ll need to take PEP for 28 days.
• Clean injection equipment prevents HIV being passed through intravenous drug use.
• Condoms can prevent the spread of HIV if you use them consistently and correctly for anal and vaginal sex.
• Undetectable = Untransmittable (U=U) means that there is no risk of HIV being passed during sex if the person living with HIV has had an undetectable viral load on HIV medications for at least 6 months. We don’t have enough data to know if being undetectable prevents HIV transmission from sharing injection equipment.

This information is provided by San Francisco City Clinic.

Visit our homepage at sf.gov/cityclinic.

Information last revised October 2025