What Is HIV? HIV (human immunodeficiency virus) is a virus that attacks the immune system. AIDS (acquired immune deficiency syndrome) happens after someone has had HIV for many years. In AIDS, the immune system is severely weakened. People with AIDS get serious infections and health problems. How Does HIV Spread? HIV spreads when infected blood, semen ("cum") or vaginal fluids enter the body. Because symptoms can be mild at first, people with HIV might not know they're infected. They can spread HIV to others without knowing it. HIV can spread: during sex (especially anal sex and vaginal sex) through sharing needles for injecting drugs or tattooing by getting stuck with a needle with an infected person's blood on it HIV also can pass from mother to child during pregnancy, childbirth, or breastfeeding. HIV does not spread through: pee, poop, spit, throw-up, or sweat (as long as no blood is present) coughing or sneezing holding hands sharing eating utensils or drinking glasses How Can I Protect Myself? The best way to protect yourself from HIV is to not have sex (vaginal, oral, or anal) and not share needles. If you decide to have sex, reduce your risk of getting HIV by: using a condom every time you have sex (including vaginal, oral, or anal sex) getting tested for HIV and making sure all partners do too reducing the number of sexual partners you have getting tested and treated for STDs (sexually transmitted diseases); having an STD increases the risk of HIV infection Understanding how HIV spreads can help you make safer choices about sex. Talk to your doctor if you have any questions about HIV and if you want to get tested. Back to Articles Related Articles HIV and AIDS There is no cure for AIDS, which is why prevention is so important. Get the facts on HIV/AIDS, as well as how it affects the body and is treated, in this article. Read More How to Get Tested for HIV Often the only way to know if someone is infected with HIV is through testing. Here are the facts on what's involved in getting tested — and who should get tested for HIV and why. Read More Can You Get HIV From Having Sex With Someone Who Has AIDS? Find out what the experts have to say. Read More Talking to Your Partner About STDs You know you should talk about sexually transmitted diseases (STDs) before the action starts. But what if the thought of having "the talk" makes you nervous? These tips can help. Read More Telling Your Partner You Have an STD People who have STDs might feel apprehensive about discussing their disease with a partner. Here are some tips on talking to a partner when you have an STD. Read More Talking to Your Partner About Condoms Some people - even those who are having sex - are embarrassed by the topic of condoms. Here are some tips for talking about condoms with your partner. Read More STDs (Sexually Transmitted Diseases) You've probably heard lots of discouraging news about sexually transmitted diseases. The good news is that STDs can be prevented. Find out how to protect yourself. Read More About Birth Control Before you consider having sex, you need to know how to protect yourself. Read this article to get the basics on birth control. Read More My Friend Has HIV. How Can I Help? People who have HIV might feel alone and frightened at times. More than anyone, they need good friends like you to lean on and trust. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.