STD Quiz: Symptoms, Testing & List

No contraception is 100% effective against STDs. Abstinence is the only way to prevent STDs totally, but condoms are a great way to reduce the possibility of getting one.

Sexually transmitted diseases (STDs) are contagious, even in the early stages when there may be no symptoms. In addition, many STD symptoms may not seem related to an STD, such as stomach pains. If you are sexually active it is important to get tested for STDs, even if you don't have symptoms or if you have symptoms that seem unrelated.

Genital herpes is very common. An estimated 40 to 50 million people in the U.S. have genital herpes, with 776,000 new cases being reported each year. An estimated 60% of sexually active adults carry the herpes virus.

Hand-foot-mouth disease is not a sexually transmitted disease. Public lice or "crabs" is a type of ectoparasitic infection, which refers to infections caused by tiny parasitic bugs or mites. Urethritis (inflammation of the urethra) may be caused by the same germs that can cause STDs and symptoms include a burning sensation during urination, and thick or watery discharge. A chancroid is a type of bacteria that is transmitted during sexual contact, and it causes painful, open sores about 4 to 10 days after infection.

Gonorrhea is a sexually transmitted disease and it cannot be transmitted from toilet seats or other surfaces such as door handles. The bacterium that causes gonorrhea, Neisseria gonorrheae, cannot survive outside the body for more than a few minutes. Neisseria gonorrheae requires very specific conditions including moist surfaces within the body such as the vagina and cervix. If the bacterium that causes gonorrhea infects the Fallopian tubes, this can lead to a painful condition called pelvic inflammatory disease (PID).

If left untreated, syphilis can lead to deafness and can even be fatal in the later stages. The primary stage of syphilis is the formation of a painless sore (chancre) in the location where the infection entered the body (usually the vagina or anus). The secondary stage causes rashes that do not itch on several parts of the body. There may be a latent, or hidden, stage of syphilis when the primary and secondary symptoms disappear. If syphilis is left untreated, it can reach the late stage where internal organs may be damaged, and symptoms include deafness, blindness, paralysis, and dementia. The organ damage may be severe and can lead to death.

While some people may not experience any symptoms, painful urination, painful sex, and bumps, sores, or warts near the mouth, anus, or vagina are all possible signs and symptoms of sexually transmitted diseases. Other symptoms of STDs include swelling or redness near the penis or vagina, severe itching near the penis or vagina, penile or vaginal discharge, vaginal bleeding other than a monthly period, skin rash, weight loss, loose stools, night sweats, aches, pains, fever, and chills.

In addition to chlamydia, the bacterium Chlamydia trachomatis can cause lymphogranuloma venereum (LGV), orchitis, epididymitis, and urethritis. Lymphogranuloma venereum causes lesions that may resemble herpes, and it affects the genitals, anus, or rectum. Orchitis (inflammation of the tube connecting the urethra and the testicles) and epididymitis cause inflammation in parts of the testicles, and urethritis (inflammation of the urethra) in men causes a burning sensation during urination and a thick or watery discharge.

Hepatitis C causes liver inflammation and is a blood-borne virus, typically spread by exposure to infected blood. This usually happens from sharing needles during drug use, tattooing, and piercing. Unlike hepatitis B, hepatitis C is only rarely transmitted through sexual contact.

Kaposi's sarcoma is caused by the Kaposi sarcoma associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8). It is a type of skin tumor characterized by red or purple skin lesions. In most cases, KSHV alone does not cause Kaposi's sarcoma, but when a person with a weakened immune system such as those with HIV infection are exposed to the virus, they may develop the illness. Human herpesvirus 8 has been isolated in the semen of men infected with HIV, which is part of the basis for suspecting it as a sexually transmitted disease.

The Centers for Disease Control (CDC) estimates there are more than 1.2 million people in the U.S. living with HIV, the virus that causes AIDS. Nearly 660,000 people have died from the infection overall.

Condoms are highly effective in reducing the spread of HIV when they are used correctly and consistently. However, even when used properly, there is still a chance of passing on HIV if condoms are the only protection used. Condoms are also useful in preventing other sexually transmitted diseases that are passed through bodily fluids, including gonorrhea and chlamydia. They are not as effective in protecting against STDs that are spread by skin-to-skin contact such as syphilis, genital herpes, and human papillomavirus (genital warts). Talk to your doctor about the best ways to prevent the spread of HIV and other STDs.

Unfortunately, kissing can spread a number of infections. The most common STD transmitted through kissing is herpes, which causes cold sores. Syphilis and HPV (warts) may rarely be spread through kissing.