The Most Common Sexually Transmitted Diseases
Acquired Immunodeficiency Syndrome (AIDS)

AIDS, first reported in the US in 1981, is caused by the HIV virus, which destroys the body’s ability to fight infection. One million people are currently infected in the US including more than 2000 infants who contracted the disease from their mothers. People with AIDS are more susceptible to life-threatening diseases and certain forms of cancer.
The virus is transmitted primarily through sexual activity and through sharing needles used to inject intravenous drugs.
Chlamydia
Chlamydia infection is now the most now the most common of all sexually transmitted diseases. Four million new cases occur each year. Chlemydial infection causes abnormal genital discharge and burning with urination for both men and women. For women, untreated chlemydial infection may lead to PID—one of the leading causes of infertility in women. Many people with chlmaydial infection have little symptoms of infections. Chlamydial infections can be treated with an antibiotic drug once diagnosed.
Genital Herpes (Herpes Simplex Virus)
Genital herpes affects 30 million Americans. 500,000 new cases of this infection develop each year. Major symptoms of herpes infection include painful blisters and open sores in the genital area. The sores disappear within two to three weeks, but the virus remains in the body and the lesions recur in cycles. Acyclovir can be used to treat severe genital herpes; however, it does not remove the virus itself from the body. Women who acquire genital herpes during pregnancy may transmit the virus to their babies.
Genital Warts
Genital warts are caused by a virus related to the virus that causes common warts on other parts of the body. Genital warts appear as small, hard, painless bumps in the penis, vaginal area, or anus. If left untreated, these bumps might grow and develop a fleshy, cauliflower appearance. Genital warts infect 500,000 Americans each year, and scientists believe that the virus responsible for genital warts may also cause several kinds of genital cancer. Genital warts can be removed by surgery, treated with a topical medication, or frozen with injections of interferon.
Gonorrhea
Approximately one million cases of gonorrhea occur each year in the US. Symptoms of gonorrhea include painful urination and discharge from the vagina or penis. As with chlamydial infections, gonorrhea may lead to PID and infertility. Antibiotics or a combination of drugs can be used to treat gonorrhea. 
Syphilis
Symptoms of syphilis are mild and disappear spontaneously. The initial symptom is a painful, open sore that appears in the vagina or penis. Syphilis might progress into more advanced stages and eventually affects the heart and central nervous system. It might take years for the disease to progress. This disease is often treated with penicillin.