HIV attacks the immune system, and as of CDC's 2023 surveillance about 1.12 million people in the US are living with it, with roughly 38,800 newly diagnosed that year CDC AtlasPlus, 2023. Diagnoses cluster in the South. There's no cure, but treatment lets people live near-normal lifespans and, when undetectable, not transmit it.
in 2023
≈723,000 — U=U
| Item | Value |
|---|---|
| New diagnoses | 38,800 — in 2023 |
| Living with HIV | 1.12 million |
| Virally suppressed | ~65% — ≈723,000 — U=U |
| On PrEP | 381,000 |
What HIV actually is
HIV is a virus that attacks the body's immune system, and it moves through three stages CDC, About HIV. The acute stage carries a very high viral load and is the most contagious. The chronic stage, or clinical latency, can last a decade or more untreated while the virus stays quietly active. AIDS is the most severe stage, defined by a CD4 count under 200 cells/mm³ or an opportunistic infection.
HIV isn't curable, but it's manageable StatPearls. Once someone has HIV they have it for life, yet with treatment they can live long, healthy lives and protect their partners. A 20-year-old who starts treatment before their CD4 count drops below 200 now has a life expectancy approaching the general population's Lancet HIV.
Symptoms — and the silent reality
About 90% of people develop flu-like symptoms 2 to 4 weeks after infection, called acute retroviral syndrome hiv.gov. These can include fever, chills, rash, night sweats, muscle aches, sore throat, fatigue, swollen lymph nodes, and mouth ulcers.
Those early symptoms look exactly like the flu, and some people have none at all. Symptoms can neither confirm nor rule out HIV; only a test can. After the acute phase comes clinical latency, often years without symptoms, when people most often miss it.
That acute window matters in practice. Symptoms appear 2 to 4 weeks after infection, right when the viral load peaks above a million copies/mL, so onward transmission risk is at its highest. If you have flu-like symptoms after a recent risk, treat it as a reason for an urgent test.
How HIV spreads
Only certain body fluids carry enough virus to transmit HIV: blood, semen, vaginal fluid, rectal fluid, and breast milk CDC, How HIV Spreads. The main routes are anal or vaginal sex, sharing needles or injection equipment, and perinatal transmission during pregnancy, childbirth, or breastfeeding.
The virus doesn't spread through saliva or kissing, casual contact, surfaces, food, donating blood, insects, water, or air, and it doesn't survive long outside the body.
Perinatal transmission is largely preventable. With ART during pregnancy and labor plus newborn prophylaxis, the risk of passing HIV to a baby drops below 1%.
How HIV is tested
Testing is the only way to know your status, and it's faster than people expect. A finger-stick or oral-swab rapid test gives results in minutes, a lab blood test is also an option, many health departments offer it free, and at-home kits exist. There is also a window period, the gap between exposure and when a test can reliably detect infection.
Different tests have different windows after exposure CDC, HIV Testing:
| Test type | Detection window after exposure |
|---|---|
| Nucleic-acid test (NAT) | 10–33 days |
| Antigen/antibody (4th-gen) lab test | 18–45 days |
| Antibody / rapid tests | 23–90 days |
A negative result is conclusive only after the full window with no exposure during it. The USPSTF gives a Grade A recommendation to screen everyone ages 15–65 at least once, and the CDC advises at least annual testing for anyone at increased risk USPSTF Grade A. For more on timing your test, see our guides on the hiv testing window and when to test after exposure — and you can get tested or compare testing providers.
Treatment
Everyone with HIV should start antiretroviral therapy (ART) as soon as possible after diagnosis CDC, HIV Treatment. It's lifelong, and the goal is an undetectable viral load. ART combines HIV medicines — single-pill and combination options exist, drawing on drug classes including integrase inhibitors, NRTIs, NNRTIs, and protease inhibitors.
Modern HIV care turns on U=U: undetectable equals untransmittable. A person who takes their medicine as prescribed and stays virally suppressed will not transmit HIV to sex partners CDC, U=U. Across the PARTNER, Opposites Attract, and PARTNER2 studies, mixed-status couples logged more than 125,000 condomless sex acts with zero linked transmissions while the partner with HIV was undetectable PARTNER, Lancet. Most people reach undetectable within six months of starting ART. For details on regimens, see our hiv treatment guide.
Treatment is not a cure. ART controls the virus and drives it to undetectable, but latent HIV reservoirs persist in cells and tissues, and the virus rebounds if treatment stops HHS clinicalinfo. A few people have achieved long-term remission after stem-cell transplants done to treat cancer — the Berlin and London patients and a New York woman documented in 2022 — but those used rare HIV-resistant donor cells, are high-risk, and aren't a scalable cure NIH, 2022. A cure remains a research goal.
Complications if untreated
Left untreated, HIV progresses to AIDS — a CD4 count under 200 cells/mm³ or the appearance of an opportunistic infection (an illness that takes hold because the immune system is too weakened to fight it off). AIDS is the most severe stage. For more on what those infections involve, see our page on hiv complications.
Prevention
The CDC's core prevention toolkit is condoms, PrEP, PEP, treatment-as-prevention (U=U), and regular testing CDC, PrEP. PrEP is for people without HIV who are exposed through sex or injection drug use, and it cuts HIV risk from sex by about 99% and from injection drug use by at least 74% when taken as prescribed.
- Daily oral PrEP comes as Truvada (emtricitabine/tenofovir disoproxil fumarate) or Descovy (emtricitabine/tenofovir alafenamide) — but Descovy isn't approved for people at risk through receptive vaginal sex or for those who inject drugs, while Truvada covers all those routes.
- Long-acting injectable cabotegravir (Apretude) is given as two initiation doses a month apart, then every two months.
- PrEP requires a confirmed HIV-negative test before starting and at follow-ups — every 3 months for oral, every 2 months for injectable — plus baseline kidney-function, hepatitis B, and STI screening; starting PrEP with undiagnosed HIV risks drug resistance.
- Twice-yearly injectable lenacapavir produced zero infections among women in the PURPOSE 1 trial, the strongest HIV-prevention result yet WHO.
If you think you've already been exposed, PEP can still prevent infection, but it must start within 72 hours and be taken daily for 28 days CDC, PEP. The original occupational study found it cut seroconversion by about 81%, so treat it as an emergency, same-day conversation rather than a wait-and-test one. PEP is for emergencies only and isn't a substitute for PrEP or condoms.
When to see a clinician
Get tested if you've never been screened, if you have ongoing risk (test at least yearly), or if you have flu-like symptoms after a possible exposure. If a possible exposure happened within the last 72 hours, don't wait for a test — go to urgent care or an ER and ask about PEP today. And if you're HIV-negative with ongoing risk, ask about PrEP as a forward-looking plan.