STD & HIV Basics

What are STDs and HIV?

Gonorrhea, Chlamydia, Syphilis, HPV

STD stands for “sexually transmitted disease.” Some common STDs include gonorrhea, chlamydia, syphilis, and HPV (human papillomavirus) —you may have also heard people call them “the clap,” “the drip,” or “warts.” Anyone can get these and other STDs. They are very common, especially among young adults. Most people who have chlamydia, gonorrhea, or HPV don’t know it—they often don’t have any symptoms.

You can easily pass STDs even if you don’t have symptoms! If you don’t treat STDs, they can lead to serious health problems.

Be careful: Washing the genitals, urinating, or douching after sex will not prevent an STD! Some ways to prevent STDs are: 1) use condoms the right way every single time you have sex, 2) have sex only with someone who’s STD-free, and who has sex only with you, or 3) don’t have sex.
Learn more about STDs on the CDC STD website »


To understand what HIV is, let’s break it down:

  • H – Human – This particular virus can only infect human beings.
  • I – Immunodeficiency – HIV weakens your immune system by destroying important cells that fight disease and infection. A “deficient” immune system can’t protect you.
  • V – Virus – A virus can only reproduce itself by taking over a cell in the body of its host.

HIV is a lot like other viruses, but there is an important difference – over time, your immune system can clear most viruses out of your body. That isn’t the case with HIV – the human immune system can’t seem to get rid of it. HIV can hide for long periods of time in the cells of your body and attacks a key part of your immune system – your T-cells or CD4 cells. Your body has to have these cells to fight infections and disease, but HIV invades them, uses them to make more copies of itself, and then destroys them.

Over time, HIV can destroy so many of your CD4 cells that your body can’t fight infections and diseases anymore. When that happens, HIV infection can lead to AIDS.

AIDS stands for:

  • A – Acquired – AIDS is not something you inherit from your parents. You acquire AIDS after birth.
  • I – Immuno – Your body’s immune system includes all the organs and cells that work to fight off infection or disease.
  • D – Deficiency – You get AIDS when your immune system is “deficient,” or isn’t working the way it should.
  • S – Syndrome – A syndrome is a collection of symptoms and signs of disease. AIDS is a syndrome, rather than a single disease, because it is a complex illness with a wide range of complications and symptoms.

AIDS is the final stage of HIV. People at this stage of HIV disease have badly damaged immune systems, which put them at risk for opportunistic infections (OIs).

Learn more about HIV and AIDS at »

How do people get STDs and HIV?

You can get HIV, gonorrhea, chlamydia, syphilis, or HPV from having sex. They are spread when fluids containing HIV or another STD from one person enter the body of another person. These fluids include:

  • Blood
  • Semen (cum)
  • Pre-seminal fluid (pre-cum)
  • Vaginal fluid
  • Breast milk (for HIV only)

HIV can enter the body through:

  • Lining of the anus or rectum
  • Opening to the penis
  • Mouth that has sores or bleeding gums
  • Cuts and open wounds
  • Lining of the vagina and/or cervix
  • Needles (hypodermic syringes)

Can I get HIV or other STDs from shaking someone’s hand? from kissing him?

You cannot get HIV or other STDs from:

  • Contact with unbroken skin, saliva, sweat, or tears of someone who has HIV.
  • Shaking the hand of someone with HIV or touching something they have touched (like exercise equipment) or breathing the same air.
  • Closed-mouth kissing, however there is a remote risk that it can be spread through French (open-mouthed) kissing if someone has bleeding gums or open wounds and blood is exchanged.
  • Mosquitos.

Certain sexual activities are risker than others. Learn more about the different risks associated with different activities

For more information about how HIV can be spread (or not spread), check out the CDC’s Transmission FAQSource:

How do you know if you have an STD or HIV?

The only way to know for sure if you have HIV or another STD is to get tested.


Many STDs don’t have symptoms, but a few things to look out for are:

  • Pain or burning when you go pee
  • Sores or warts on your penis, mouth, anus, or rectum
  • Discharge from your penis
  • Painful or swollen testicles
  • Rash
  • Body aches
  • Feeling really tired


Many people don’t have symptoms when they have HIV, but a few things to look out for are:

  • Body aches
  • Feeling really tired
  • Fever
  • Chills
  • Rash
  • Night sweats
  • Sore throat
  • Swollen lymph nodes
  • Sores in the mouth

Looking for an HIV or other STD testing location near you? Visit: Know your status »

How are gay, bisexual, & other men who have sex with men affected by HIV & other STDs?

According to the U.S. Centers for Disease Control and Prevention (CDC)*:

    • Men who have sex with men (MSM) account for nearly half of the more than one million people living with HIV in the U.S. (48%, or an estimated 532,000 total persons).
    • MSM account for more than half of all new HIV infections in the U.S. each year (53%, or an estimated 28,700 infections).
    • While CDC estimates that MSM account for just 4% of the U.S. male population age 13 and older, the rate of new HIV diagnoses among MSM in the U.S. is more than 44 times that of other men (range: 522–989 per 100,000 MSM vs. 12 per 100,000 other men).

*Statistics from: CDC, HIV and AIDS among Gay and Bisexual Men, Accessed on 7/15/11.

Other sources:,, GYT Campaign (Get Yourself Tested)