Sexually transmitted diseases (STDs) are at epidemic levels in the United States and worldwide. Three common STDs among college students are chlamydia, HPV, and herpes.

Chlamydia is often asymptomatic, especially in women. In men, it produces a thin discharge from the penis and mild pain on urination. It is quite curable with antibiotics. If left untreated in women, the possible complications include pelvic inflammatory disease and possibly infertility.

HPV (human papillomavirus) causes genital warts. Sometimes the warts are obvious, but in other cases they are small and may not be visible. HPV infection increases women's risk of cervical cancer.

Genital herpes, caused by the HSV virus, produces bouts of painful blisters on the genitals. These episodes may recur for the rest of the person's life, although some infected persons experience no or only a few outbreaks. Currently there is no cure, although the drug acyclovir minimizes the symptoms. Herpes infection increases one's risk of HIV infection.

The virus HIV destroys the body's natural immune system and leaves the person vulnerable to certain kinds of infections and cancers that lead to death. Most HIV-positive people come from three risk groups: men who have sex with men, injection drug users, and heterosexual partners of infected persons. Drugs such as AZT and ritonavir (a protease inhibitor) are used to slow the progression of the disease. More attention needs to focus on the special concerns of HIV-infected women and ethnic minorities. Several strategies for producing a vaccine are being pursued.

The primary symptoms of gonorrhea in the male, appearing two to five days after infection, are a white or yellow discharge from the penis and a burning pain on urination. The majority of women with gonorrhea are asymptomatic. Gonorrhea is caused by a bacterium, the gonococcus, and is cured with antibiotics. If left untreated, it may lead to infertility.

Syphilis is caused by the bacterium Treponema pallidum. The first symptom is a chancre. Penicillin is effective as a cure. If left untreated, the disease progresses through several stages that may lead to death.

Hepatitis B, caused by the virus HBV, is transmitted sexually as well as by needle sharing. Antiviral drugs are available to treat chronic cases. A vaccine is now available and administered widely.

Pubic lice are tiny lice that attach to the pubic hair. They are spread through sexual and other types of physical contact. Shampoos are available for treatment.

Techniques for preventing STDs include thorough washing of both partners' genitals before intercourse; urination both before and after intercourse; inspecting the partner's genitals for symptoms like a wart or urethral discharge; and the use of a condom.

Other vaginal infections include monilia, trichomoniasis, and bacterial vaginosis. Cystitis is an infection of the urinary bladder in women, leading to frequent, burning urination. Prostatitis is inflammation of the prostate gland.