Sexually Transmitted Diseases (STDs), also known as venereal diseases, are infectious diseases passed from one person to another during sexual contact. STDs are one of the most common infections known. There are more than 12 million people in the United States infected with STDs every year. A reported 3 million of those people are teenagers. One out of ten Americans will contract a STD during his or her lifetime. People who do not know they are infected risk infecting their sexual partners and, in some cases, their unborn children. If left untreated, these diseases may cause extreme pain or may destroy a woman's ability to have children. .
Some STDs can be cured with a single dose of antibiotics, but many, such as AIDS, cannot be cured. People with these diseases remain infected for their entire lives. People who have unprotected sex are most likely to contract a STD, those who have multiple partners, and whose sex partners include drug users who share needles. Studies show that Americans between the ages of 16 and 24 are at bigger risk of catching STDs than older adults. This is because younger people are more likely to have multiple sexual partners rather than a committed relationship. Young people may also be more likely to have unprotected sex and may be embarrassed to tell their sexual partners they are infected or unable to seek medical attention for STDs. This means that they are not only more likely to pass the disease to other young people but have a greater risk of suffering the long-term effects of untreated STDs. .
STDs are transmitted by infectious agents called microscopic bacteria, viruses, parasites, fungi, and single-celled organisms called protozoa that thrive in warm, moist environments in the body, such as the genital area, mouth, and throat. Most STDs are spread while having sex, but other forms of sexual contact, such as oral sex, can also spread disease.