Definition

A disease caused by infection with certain bacteria, viruses, or other microorganisms that can be passed from one person to another through blood, semen, vaginal fluids, or other body fluids, during oral, anal, or genital sex with an infected partner. These diseases can also be spread through sharing needles, blood transfusions, breastfeeding, or from an infected mother to an infant during pregnancy and childbirth. Symptoms of sexually transmitted infections may include sores, blisters, or bumps on the genitals or in the mouth or rectal area, pain or burning during urination or sex, unusual drainage or bleeding from the penis or vagina, itching and redness in the genital or anal area, pain in the lower abdomen, fever, and sore, swollen lymph nodes, especially in the groin. There are many types of sexually transmitted infections, including human papillomavirus (HPV), HIV, genital herpes, chlamydia, gonorrhea, and syphilis. If not treated, some sexually transmitted infections can lead to long-term health problems. Also called sexually transmitted disease, STD, and STI.