Human immunodeficiency virus (HIV)

Human immunodeficiency virus (HIV) affects your immune system, which is your body’s natural way of fighting infections. Without treatment, your immune system may become so weakened that it’s hard to stay healthy. But most people who are treated for HIV live long, healthy lives, making ongoing care an essential part of staying well.

Infectious disease experts in Penn Medicine’s HIV Clinics provide expert, person-centered HIV care. We offer preventive strategies and therapies to lower your risk of getting the virus. If you’re diagnosed with HIV, our specialists provide advanced treatments and continuous support throughout your lifetime. We partner with you to help you stay healthy, manage related conditions, and maintain a strong immune system.

In the early stages of HIV, you may have mild symptoms or none at all. Because of this, the only reliable way to know if you have HIV is through testing. Without treatment, HIV can cause more noticeable symptoms over time.

The stages of HIV and common symptoms include:

• Acute HIV infection: Within two to four weeks of becoming infected, HIV may cause flu-like symptoms, including a fever, headache, muscle aches, rashes, or a sore throat. These symptoms usually last a few days to a few weeks and go away, but the virus remains in your body.
• Chronic HIV infection: During this stage, HIV continues to affect the immune system, but most people don’t feel sick or have visible symptoms. This stage can last for many years if treatment isn’t started.
• Advanced or late-stage HIV: If HIV goes untreated, it can severely weaken the immune system, making it harder to fight off other infections or certain cancers. These are called opportunistic infections. Symptoms may include persistent fever, fatigue, night sweats, weight loss, swollen lymph nodes, diarrhea, or recurrent rashes.

HIV affects the immune system by targeting a type of white blood cell called a CD4 cell, which helps the body fight infection. Over time, if HIV isn't treated, it can weaken the immune system and make it harder to stay healthy.

HIV is transmitted through contact with certain body fluids from a person who has the virus. Specifically, it can be transmitted through blood, semen, vaginal fluids, rectal fluids, and breast milk. The most common ways HIV is spread is through:

• Having sex without a condom or without preventive medication (PrEP or PEP)
• Sharing needles, syringes, or other equipment when injecting drugs
• Transmitting the virus from a pregnant person to their baby during pregnancy, childbirth, or breastfeeding, though treatment can reduce this risk to nearly zero

You can’t get HIV from casual contact, like hugging, shaking hands, sharing food or utensils, using the same bathroom, or touching surfaces. Everyday interactions are completely safe.

Many people living with HIV don’t have symptoms at first, so the only way to know if you have it is through testing. Routine HIV screening detects the virus early, allowing treatment to begin right away, which keeps your immune system strong and prevents transmission to others. HIV tests may be part of routine medical care, like during pregnancy or annual health checkups. Depending on your personal health and risk factors, your doctor may recommend testing more often.

HIV is diagnosed with a simple test that checks a sample of your blood or saliva for signs of the virus. Rapid tests can give you results the same day, while other test results may take a few days. You can take an HIV test at your doctor’s office, at a clinic, or through a self-test at home. Anyone who has a positive result needs follow-up testing with a health care provider to confirm the diagnosis. Getting tested is quick and confidential.

HIV isn’t curable, but a combination of medications can stop the virus from replicating to treat your symptoms and strengthen your immune system. These medications are known as antiretroviral therapy (ART), and they may be taken as daily pills or long-acting injections. With consistent treatment, the amount of virus in your blood can drop to undetectable levels. This means the virus can’t be passed to others.

Because HIV remains in the body even when undetectable, treatment needs to continue throughout life. Taking ART as prescribed and having regular follow-up with your health care team are key to maintaining good health and preventing transmission.

Preventing HIV starts with understanding HIV transmission and taking steps to lower your risk of getting it. Using condoms correctly and consistently during sex is one of the most effective ways to prevent HIV. Choose latex or polyurethane condoms and water-based lubricants, since oil-based products can cause condoms to break down.

Avoid sharing needles, syringes, or any equipment used for injecting drugs, hormones, or other substances. Using new, sterile supplies every time helps prevent HIV and other infections such as hepatitis B and C.

Medications that prevent HIV

Some people benefit from preventive medications. Pre-exposure prophylaxis (PrEP) is a medication that significantly lowers your risk of getting HIV if you’re exposed to the virus. Post-exposure prophylaxis (PEP) may be an option if you’ve had a possible exposure to HIV. PEP must be started within three days of exposure and taken for 28 days.

Both PrEP and PEP are prescribed by a health care provider. There are emergency numbers you can call for assistance with these medications. Call the PrEP hotline at 267-601-5332 or the PEP hotline (for Philadelphia residents only) at 833-933-2815. Lancaster residents can access PEP at LG Health Comprehensive Care.

At Penn Medicine, we’re committed to status-neutral HIV care, meaning that everyone, regardless of HIV status, receives respectful, comprehensive care. Our clinics provide HIV prevention and treatment, along with care for other sexually transmitted infections (STIs). If you test positive for HIV, we create an ART treatment plan that can help you live a long, healthy life. We also have experts who can treat multiple infections at once, like HIV and hepatitis C, at the Penn Medicine Co-Infection Clinic. Our social workers and case managers offer emotional support, help coordinate care, and assist with accessing medical services, including for people without insurance coverage.

Our clinical care is deeply connected to research and innovation. Our scientists are leading studies to improve HIV prevention, treatment, and cure strategies. Through our HIV Clinical Trials Unit, funded by the National Institutes of Health, Penn researchers have helped shape the national standard of treatment and prevention of HIV. These initiatives mean you may have an opportunity to participate in clinical trials at Penn Medicine, and that you can trust you’re getting the most advanced care possible.