This document discusses sexually transmitted diseases (STDs), including syphilis, gonorrhea, and AIDS. It describes the causative agents, modes of transmission, symptoms, stages of disease progression, and treatments for each STD. STDs are caused by bacteria, viruses, parasites, and fungi transmitted through sexual contact or blood exposure. Common symptoms include sores, rashes, and discharge. Treatments involve antibiotics or antiviral drugs. Prevention methods include condom use, limiting partners, safe needle practices, and blood screening.