1. sharing a drink
   sex
2. sharing a needle

HIV is not spread through casual contact. That means you can share a drink or even a kiss with an infected person and not catch it. HIV is spread by sex, sharing needles and other more invasive methods of swapping blood.

1. cervical cancer
   liver cancer
2. skin cancer

HPV infection can result in genital warts, which is bad enough, but left untreated it can also result in cervical and other cancers. Fortunately, some types of HPV can be prevented with a readily-available vaccine.

1. ask your partner if they have one
   keep an eye out for symptoms
2. get tested

Many STIs have no symptoms at all, while others have symptoms that can be confused with other conditions. The best way to know your status is to get tested for STIs.

1. antibiotics
   anti-viral medicine for life
2. there is no treatment

Chlamydia is one of the more common STIs and often causes burning, pain and abnormal discharge. Fortunately, it can be treated with a single round of antibiotics.

1. never
   when you're with the same partner
2. anytime the condom looks undamaged

Reusing a condom leaves you exposed to STIs and pregnancy. Always dispose of condoms after each use and grab a new one every time you have sex.

1. penetrative sex
   oral sex
2. both penetrative and oral sex

Don't think that a lack of penetration makes oral sex safe. All forms of sex, including oral, can transmit STIs, including HIV.

1. have sex with one partner at a time
   use condoms
2. abstain from all forms of sex

The only way to be 100 percent sure you won't get an STI is to abstain from all forms of sex. Since this simply isn't practical for many adults, you can reduce your risk of picking up an infection by using condoms and avoiding risky behaviors.

1. washing after sex
   douching after sex
2. wearing a condom during sex

Don't fall for the rumors: washing, douching or urinating after sex won't prevent you from picking up an STI if your partner is infected. The only way you can truly protect yourself is to abstain from sex or use condoms.

1. chlamydia
   HIV
2. herpes

While many STIs can be cured, others can only be managed because science has yet to find a cure. Both HIV and herpes are life-long illnesses, but chlamydia can be cured with a strong dose of antibiotics.

1. gonorrhea
   syphilis
2. HPV

Both HPV and Hepatitis B can largely be prevented with vaccinations. Many babies get a Hep B vaccine, and the HPV vaccine is often given during the teen years.

1. gonorrhea
   syphilis
2. herpes

The herpes virus is transmitted through all forms of sex, and people suffering from this STI experience outbreaks of painful blisters and sores in the genital region.

1. in your car
   in your bedroom
2. in your pocket

Condoms should be stored in a cool, dry place. That means keep them in your dresser or nightstand and not in a place like your pocket or car, which can get too hot and damage the condoms -- limiting their effectiveness.

1. penetrative sex only
   from toilet seats
2. any sexual contact

Pubic lice, aka crabs, can be caught via any sexual contact. That means you don't actually have to have intercourse to get them -- you can get them from simply lying naked near an infected person. An over-the-counter medicine eliminates almost every pubic lice infection if used correctly.

1. 2 percent
   25 percent
2. 90 percent

One in four teens picks up an STI each year. By age 25, 50 percent of all adults will have had at least one STI. This means that using condoms and undergoing regular testing are particularly important for youth within that age group.

1. 1 percent
   15 percent
2. 85 percent

Around 15 percent, or one in seven Americans with HIV don't know they have it. Protect your partners and know your treatment options by getting tested if you suspect you could have HIV.

1. gonorrhea
   syphilis
2. HIV

Gonorrhea has long been known as the clap. This may be linked to an old French term for brothel -- clapier -- where this STI ran rampant.

1. about a third
   around 75 percent
2. more than 95 percent

When it comes to taking charge of your sexual health, knowledge is power. Keep in mind that only about a third of all doctors include STI testing as part of a standard health screen. That means with most doctors, if you want an STI test, you'll have to ask.

1. 5 percent
   50 percent
2. 95 percent

Around half of the population will pick up an STI at some point in their lifetime. While many of these conditions are treatable, others are not. Incurable infections can only be managed to minimize impact.

1. 15 to 24
   35 to 44
2. 65 and up

Young people between the ages of 15 and 24 account for around 50 percent of all new STI diagnoses each year, even though people in this age group represent only around a quarter of the sexually active population in the U.S.

1. 20 percent
   50 percent
2. 80 percent

Around 20 percent of the population, or one in five adults, have genital herpes. Even worse, 90 percent of them don't know it, making it easy to spread the disease to their partners.

1. herpes
   HIV
2. HPV

HPV, or human papillomavirus, is by far the most common STI in America. Nearly everyone who is sexually active will be infected at some point in their lives.

1. a rash over the entire body
   a painless red sore
2. syphilis never has any symptoms

Most cases of syphilis reveal themselves with only a single sore. It's red, painless, round, and generally found on either the mouth or genitals. If you spot a sore like this, get treated, because later stages of syphilis pose some serious health risks.

1. herpes
   HIV
2. gonorrhea

Herpes doesn't require sexual penetration to spread -- it spreads by simple contact with sores. That means a condom won't prevent transmission, especially if your partner has sores in an area not covered by the condom.

1. a parasite
   bacteria
2. virus

Trich is an STI caused by transmission of a parasite. Most people who have this show no symptoms, though some women develop vaginitis. A dose of antibiotics eliminates the parasite and gets rid of trich.

1. chlamydia
   herpes
2. ghonorrhea

Chlamydia is the most common STI caused by a bacterial infection. While this means it's easy to treat with antibiotics, it shouldn't be taken lightly. Left untreated, this disease can lead to pelvic inflammatory disease, which can hinder fertility.

1. in the 40s
   in the 50s
2. in the 70s

People with HIV who start taking anti-viral medicine as soon as they are diagnosed live about as long as people who don't have the disease, with an average life expectancy in the 70s in much of North America -- though people of color, people who inject illegal drugs, and those who wait too long to start taking medicine tend to die sooner.

1. having no symptoms at all
   rash on genitals
2. unexpected bleeding

Most people with gonorrhea experience no symptoms, so the only way to know if you have it for sure is to get tested. While it can be treated with antibiotics, those who leave this condition unchecked risk harming their future fertility.

1. Hepatitis B
   chlamydia
2. gonorrhea

Hepatitis B can have longstanding effects on the liver if left untreated. Even more alarming, this STI is about 50 to 100 times more infectious than HIV. Protect yourself by getting a vaccine and practicing safe sex.

1. increases risk
   decreases risk
2. has no affect on transmission risk

Male circumcision reduces the risk of HIV infection in a heterosexual male by around 60 percent. The practice also reduces the risk of developing certain other STIs, including herpes and HPV.