There are many sexual transmitted diseases that young teenagers have not seen or do not know about. According to Centers for Disease Control and Prevention (CDC), the most common sexual transmitted diseases are HIV/AIDS, genital herpes, syphilis, chlamydia, and bacterial vaginosis. Human Immunodeficiency Virus (HIV) breaks down the immune system and causes people to become sick with other infections that would not normally occur. HIV also causes acquired immune deficiency syndrome (AIDS), which is the most advanced stage of HIV. Genital Herpes is caused by two types of viruses. They are called herpes simplex type 1 and herpes simplex type 2. Genital Herpes can cause breaks in the skin or lining of the mouth, vagina, and rectum. It also increases the risk of contracting HIV. Syphilis can cause long term difficulties. The disease has a deadly stage called the latent and late stages. The latent and late stages can cause difficulty in moving your muscles, numbness, blindness, and being paralyzed. It can also damage your internal organs and can lead to death. Chlamydia can cause permanent damage to a women's reproductive system, which makes it hard or impossible to get pregnant. If not treated early, chlamydia can lead to HIV or serious health problems. For women it can spread to the uterus and fallopian tubes, causing pelvic inflammatory disease. It is rare for men to have health problems link to chlamydia, but it can happen. The infection can spread to the tube that carries sperm from the testicles, which causes pain and a fever. Bacterial vaginosis is an infection that only women can receive. The infection can produce vaginal discharge and results from unusual bacteria in the vagina. Having this infection can increase the chances of having HIV or other sexual transmitted diseases. Researchers do not know how bacterial vaginosis is caused, but they do know that having a new sex partner can upset the balance of bacteria in the vagina.