If you don't know this very basic info I pray to God that you are not sexually active. Girls always use a reliable form of birth control and insist the guy always use a condom. Guys, never do it w/o a condom--could be paying child support for the next 18 years or get a disease that can kill you. It's really that simple. sexually transmitted disease Note: All of the diseases on this list can be transmitted sexually. Some of the diseases on this list are commonly transmitted in other ways besides sexually; for example, HIV/AIDS is also commonly transmitted through the sharing of infected needles by drug users, and candidiasis, while it can be sexually transmitted, is very often not associated with sexual activity. [edit] Bacterial Chancroid (Haemophilus ducreyi) Chlamydia infection (Chlamydia trachomatis) Donovanosis (Granuloma inguinale or Calymmatobacterium granulomatis) Gonorrhea (Neisseria gonorrhoeae) Lymphogranuloma venereum (LGV) (Chlamydia trachomatis serotypes L1, L2, L3. See Chlamydia) Non-gonococcal urethritis (NGU) (Ureaplasma urealyticum or Mycoplasma hominis) Syphilis (Treponema pallidum) [edit] Viral Cytomegalovirus Hepatitis (Hepatitis A and Hepatitis E are transmitted via the fæcal-oral route, not sexually; Hepatitis C is probably not sexually transmittable) Hepatitis B Hepatitis D Herpes /HSV (Herpes simplex virus) Human Immunodeficiency Virus (HIV/AIDS) Human papillomavirus (HPV) Certain strains of HPV cause genital warts Certain strains of HPV cause cervical dysphasias which can lead to cervical cancer [edit] Parasites Pubic lice a.k.a "crabs" (Phthirius pubis) Scabies (Sarcoptes scabiei) [edit] Fungal Candidiasis (thrush) (Candida albicans) is not strictly an STD but can be transmitted through sexual contact [edit] Protozoal Amoebiasis (Entamoeba histolytica) Giardiasis (Giardia lamblia) Trichomoniasis (Trichomonas vaginalis) http://www.cyh.com/HealthTopics/HealthTopicDetails.aspx?p=240&np=299&id=2101