The Full form of STD is Sexually Transmitted Diseases. STD means they are most often, but not exclusively spread by sexual intercourse. HIV, genital warts, gonorrhea, chlamydia, genital herpes, syphilis, some forms of hepatitis, and trichomoniasis are STDs. STDs used to be called venereal diseases or VD. They are among the most common contagious diseases. More than 65 million of population in US has an incurable STD. Each year, 20 million new cases are reported; half of these infections are among people ages fifteen to twenty four and they can have long-term consequences. STDs are serious illnesses that require treatment. Some STDs, such as HIV, can be deadly and cannot be cured. By learning more about STDs, one can learn ways to protect himself. A person can get a STD from vaginal, anal, or oral sex. He can also be infected with trichomoniasis through contact with moist or damp objects such as wet clothing, towels, or toilet seats, although it is more commonly spread by sexual contact. A person is at risk if he has more than one sex partner, sex with someone who has had many partners, don’t use a condom when having sex, share needles when injecting intravenous drugs and trade sex for money or drugs.