The term sexually transmitted disease is used to cover the more than 25-30 infectious organisms that are spread through sexual activity. Sexually Transmitted Infections (STIs) are almost always spread from person to person by sexual activity. These infections are most easily spread by vaginal or anal intercourse, and sometimes by oral sex. Some STIs can also be spread through blood, particularly among intravenous (IV) drug users who may be sharing drug equipment (needles, syringes, or "works"). In addition, pregnant women with STIs may pass their infection to infants in the uterus (womb), during birth, or through breast-feeding.
Most people with STIs have no symptoms. Without treatment these diseases can lead to major health problems such as not being able to get pregnant (infertility), permanent brain damage, heart disease, cancer, and even death. If you think you have been exposed to a sexually transmitted disease, you and your sex partner(s) should visit a health clinic, hospital or doctor for testing and treatment.
Most STIs affect both men and women, but in many cases the health problems they cause can be more severe for women. If a pregnant woman has an STI, it can cause serious health problems for the baby.
If you have an STI caused by bacteria or parasites, your health care provider can treat it with antibiotics or other medicines. If you have an STI caused by a virus, there is no cure. Sometimes medicines can keep the disease under control. Correct usage of latex condoms greatly reduces, but does not completely eliminate, the risk of catching or spreading STIs.