AIDS

AIDS stands for acquired immunodeficiency syndrome. It's what can happen if someone has HIV and doesn't get treatment for a long time — their immune system gets so damaged that the body can't fight off infections. With modern medicine, HIV almost never reaches this stage anymore.

• AIDS isn't a separate virus. It's the late stage of untreated HIV.
• With today's treatment, HIV very rarely progresses to AIDS in the UK.
• People on HIV treatment can become "undetectable" — meaning they can't pass the virus on (U=U).
• HIV testing is free and confidential at sexual health clinics.
• PEP medication can prevent HIV if taken within 72 hours of exposure.

How it works

HIV attacks a type of white blood cell called CD4 cells — they're part of your immune system. If someone has HIV and doesn't take medication, the virus slowly destroys those cells over years. When enough are gone, the body can't defend itself against infections it would normally handle easily. That's when it becomes AIDS.

Why you've heard of it

AIDS was a massive crisis in the 1980s and 90s, before good treatments existed. Hundreds of thousands of people died, and there was a huge amount of fear and unfair blame — especially towards gay and bisexual men. Some of that stigma still hangs around today, even though things are medically completely different now.

What's changed

Today, someone diagnosed with HIV in the UK starts treatment called antiretroviral therapy (ART). It's usually one pill a day. It stops the virus multiplying, and most people on it live completely normal, healthy lives. Treatment can also reduce the virus to "undetectable" levels — which means it can't be passed on during sex. This is called U=U (undetectable = untransmittable).

Even someone who's been diagnosed with AIDS can recover a lot of immune function once they start treatment. An AIDS diagnosis is not a death sentence — that's an outdated idea that causes a lot of unnecessary fear.

Things people get wrong

"HIV and AIDS are the same thing." They're not. HIV is the virus. AIDS is what can happen years later if HIV isn't treated.

"You can catch it from kissing or sharing a drink." No. HIV only spreads through blood, semen, vaginal fluid, and breast milk. Not through saliva, hugging, sharing cups, or toilet seats.

"It only affects gay men." HIV can affect anyone. Worldwide, most transmission is through heterosexual sex. In the UK, gay and bisexual men are more affected, but anyone sexually active can reduce their risk with condoms and testing.

What to do if you're worried

If you think you might have been exposed to HIV, get to a sexual health clinic or A&E as fast as you can. There's a medicine called PEP (post-exposure prophylaxis) that can stop infection, but it only works within 72 hours — and sooner is better.

Where to get help

• Terrence Higgins Trust — the UK's biggest HIV charity, with info, support, and free testing.
• Sexual health clinics (GUM clinics) — free, confidential HIV and STI testing. No GP referral needed.
• NHS 111 — can point you to your nearest sexual health service, including for emergency PEP.

AIDS stands for acquired immunodeficiency syndrome. It is not a separate illness. It is what can happen if someone has the virus called HIV and does not take medicine for it over many years. Their body's defence system gets so weak that it cannot fight off infections.

In the 1980s and 1990s, before good medicine existed, many people died from AIDS. There was also a lot of unfair blame, especially towards gay and bisexual men. Some of that unfairness still exists today.

Things are very different now. Today, someone with HIV in the UK takes a tablet every day. This medicine stops the virus from spreading inside the body. Most people on this medicine live long, healthy lives, just like anyone else. The medicine is free on the NHS.

When the medicine works well, the amount of virus in the body drops so low it cannot be passed on during sex. This is called being undetectable.

HIV does not spread through kissing, sharing cups, hugging, or toilet seats. It can only spread through blood, the fluids made during sex, and breast milk. If you are ever worried you might have come into contact with HIV, go to a sexual health clinic quickly. There is a medicine that can stop you getting it, but it only works within 72 hours.