A sexually transmitted disease (STD) is an infection you can get by having sex. Some STIs (such as gonorrhea and Chlamydia) infect your sexual and reproductive organs. Others (HIV, hepatitis B, syphilis) cause general body infections.
An STI is spread during sexual activity. It is spread during vaginal, anal and oral sex. Some STIs (HIV and hepatitis B) are also spread by contact with infected blood. STIs are not normally spread by digital sex (fingering); however, unclean hands or uncut nails can cause genital problems.
Most STI germs need to live in warm, moist areas. That's why they infect the mouth, rectum and sex organs (vagina, vulva, penis and testes).
Most STIs can be cured if you seek treatment. Sometimes you can have an STI with no signs or symptoms. Other times, the symptoms go away on their own. Either way, you still have the STI until you get treated. Most STIs can be treated with antibiotics. Some STIs cannot be cured.

Chlamydia

Chlamydia is the number one sexually transmitted disease in the United States. Chlamydia is caused by the bacterium, Chlamydia trachomatis, which can damage a woman's reproductive organs. Even though symptoms of chlamydia are usually mild or absent, serious complications that cause irreversible damage, including infertility, can occur "silently" before a woman ever recognizes a problem. Chlamydia also can cause discharge from the penis of an infected man.

Chlamydia can be transmitted during vaginal, anal, or oral sex. Chlamydia can also be passed from an infected mother to her baby during vaginal childbirth.

Any sexually active person can be infected with chlamydia. The greater the number of sex partners, the greater the risk of infection. Because the cervix (opening to the uterus) of teenage girls and young women is not fully matured, they are at particularly high risk for infection if sexually active. Since chlamydia can be transmitted by oral or anal sex, men who have sex with men are also at risk for chlamydial infection.

To help prevent the serious consequences of chlamydia, screening at least annually for chlamydia is recommended for all sexually active women age 25 years and younger.

Gonorrhoea

Gonorrhea is a sexually transmitted disease (STD). Gonorrhea is caused by Neisseria gonorrhoeae, a bacterium that can grow and multiply easily in the warm, moist areas of the reproductive tract, including the cervix (opening to the womb), uterus (womb), and fallopian tubes (egg canals) in women, and in the urethra (urine canal) in women and men. The bacterium can also grow in the mouth, throat, eyes, and anus.

Gonorrhea is a very common infectious disease. Gonorrhea is spread through contact with the penis, vagina, mouth, or anus. Ejaculation does not have to occur for gonorrhea to be transmitted or acquired. Gonorrhea can also be spread from mother to baby during delivery.

People who have had gonorrhea and received treatment may get infected again if they have sexual contact with a person infected with gonorrhea.

Several antibiotics can successfully cure gonorrhea in adolescents and adults. However, drug-resistant strains of gonorrhea are increasing in many areas of the world, including the United States, and successful treatment of gonorrhea is becoming more difficult. Because many people with gonorrhea also have chlamydia, another sexually transmitted disease, antibiotics for both infections are usually given together. Persons with gonorrhea should be tested for other STDs.

Herpes Simplex I/II

Genital herpes is a sexually transmitted disease (STD) caused by the herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2). Most genital herpes is caused by HSV-2. Most individuals have no or only minimal signs or symptoms from HSV-1 or HSV-2 infection.

HSV-1 and HSV-2 can be found in and released from the sores that the viruses cause, but they also are released between outbreaks from skin that does not appear to be broken or to have a sore. Generally, a person can only get HSV-2 infection during sexual contact with someone who has a genital HSV-2 infection. Transmission can occur from an infected partner who does not have a visible sore and may not know that he or she is infected.

HSV-1 can cause genital herpes, but it more commonly causes infections of the mouth and lips, so-called "fever blisters." HSV-1 infection of the genitals can be caused by oral-genital or genital-genital contact with a person who has HSV-1 infection.

There is no treatment that can cure herpes, but antiviral medications can shorten and prevent outbreaks during the period of time the person takes the medication.

Mycoplasma genitalium

M. genitalium may be the sexually transmitted bacterium that, other than chlamydia, is a main cause of nongonococcal urethritis in men. In women, it is commonly found in association with bacterial vaginosis; M. genitalium infections can also be associated with cervicitis. Most M. genitalium infections are asymptomatic, and doctors have not yet determined whether it is worthwhile to screen everyone for infection.
M. genitalium has been associated with pelvic inflammatory disease in women. It has also been linked to endometritis (infection of the uterine lining) and preterm birth. As such, the long term consequences of infection with M. genitalium seem to be similar to those of infection with gonorrhea and chlamydia. This is not surprising since its early symptoms are also similar.

Ureaplasma genitalium

Ureaplasma Urealyticum is a bacterial infection, generally asymptomatic in nature, that is sexually transmitted between partners. The bacteria can survive in the reproductive tract for many years, undetected, until a patient is specifically tested for the infection.

Every woman who experiences infertility, recurrent pregnancy loss, pelvic pain, premenstrual symptoms or vaginal symptoms should be tested for ureaplasma urealyticum. The bacterial infection, although generally asymptomatic, can lead to fertility problems including tubal disease, recurrent miscarriages, decreased sperm motility and count, and poor post coital tests.

Treatment involves both partners simultaneously taking antibiotics prescribed by the physician to specifically treat this infection. Ninety percent of infections are effectively treated with the first course of antibiotics.

Trichomonas vaginalis

Trichomoniasis is a common sexually transmitted disease (STD) that affects both women and men, although symptoms are more common in women.

Trichomoniasis is caused by the single-celled protozoan parasite, Trichomonas vaginalis. The vagina is the most common site of infection in women, and the urethra (urine canal) is the most common site of infection in men. Women can acquire the disease from infected men or women, but men usually contract it only from infected women.

The genital inflammation caused by trichomoniasis can increase a woman's susceptibility to HIV infection if she is exposed to the virus. Having trichomoniasis may increase the chance that an HIV-infected woman passes HIV to her sex partner(s).

A person diagnosed with trichomoniasis (or any other STD) should receive treatment. Trichomoniasis can usually be cured with the prescription drug, metronidazole, given by mouth in a single dose.
Having trichomoniasis once does not protect a person from getting it again. Following successful treatment, people can still be susceptible to re-infection.

Gardnerella

Gardnerella Vaginalis is an infection of the female genital tract by bacteria of the Gardnerella vaginalis strain, often in combination with various anaerobic bacteria. Also called bacterial vaginosis.
Gardnerella vaginalis is the most common cause of bacterial vaginitis in the sexually active mature patient. The patient complains of a malodorous, nonirritating discharge, and examinations reveal homogenous, gray-white secretions.
It is assumed that the infection is sexually transmitted. The bacteria are also found in women without a history compatible with a sexually transmitted disease, and often produces no symptoms.

The treatment of choice for G vaginalis is oral metronidazole, 500 mg twice daily for 6 days. Cephradine, 500 mg by mouth 4 times daily for 6 days, will eliminate G vaginalis from the vagina and relieve symptoms but has little effect on the anaerobic flora of the vagina.

Hepatitis B

Hepatitis B is a germ (virus) that gets into your body and attacks your liver. Your liver helps your body digest the food you eat and store energy. It also helps your body get rid of poisons.

There are cases where hepatitis B can cause liver damage (cirrhosis [sir-O-sis]) that does not go away. Hepatitis B can also cause liver cancer, which may lead to death. Good medical care can make your risk less for these.

It is passed by contact with the blood or other body fluids of someone who has the virus.

1 out of every 10 adults will never get rid of the virus from their bodies. We say they have chronic hepatitis B. They are called carriers. Most people with chronic hepatitis B will remain carriers of the virus if they do not get treated.

Hepatitis C

Hepatitis C is a liver disease caused by the hepatitis C virus (HCV), which is found in the blood of persons who have this disease. HCV is spread by contact with the blood of an infected person.

Injection drug use accounts for more than two-thirds of all new infections in the United States. HCV can be spread by sex, but this is rarer.

HCV positive persons should be evaluated by their doctor for liver disease. Interferon and ribavirin are two drugs licensed for the treatment of persons with chronic hepatitis C.

HIV

HIV -- the human immunodeficiency virus - is a virus that kills your body’s "CD4 cells." CD4 cells (also called T-helper cells) help your body fight off infection and disease. HIV can be passed from person to person if someone with HIV infection has sex with or shares drug injection needles with another person. It also can be passed from a mother to her baby when she is pregnant, when she delivers the baby, or if she breast-feeds her baby.
AIDS -- the acquired immunodeficiency syndrome - is a disease you get when HIV destroys your body’s immune system. Normally, your immune system helps you fight off illness. When your immune system fails you can become very sick and can die from an illness as common as the flu.
It is important to remember that AIDS is not synonymous with HIV. AIDS results from specific damage to the immune system, and can actually be triggered by many different infections or diseases, one of which is HIV.