Stands for Sexually Transmitted Disease (also commonly known as STI - Sexually Transmitted Infection). This is an infection that is spread primarily through sexual contact, including vaginal, anal, and oral sex. Bacteria, viruses, or parasites can cause STDs. Examples include chlamydia, gonorrhea, syphilis, herpes, HPV, and HIV.

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Stands for Human Immunodeficiency Virus. This virus attacks and gradually weakens the body's immune system, specifically the CD4 cells (T cells), making the person more vulnerable to other infections and certain cancers. If left untreated, HIV can lead to the disease AIDS (Acquired Immunodeficiency Syndrome).

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