1. Chlamydia: Caused by bacteria, chlamydia usually does not manifest through outward symptoms during its early stages, but can cause health problems over the long run, if not treated at the right time.
2. HIV: Being HIV positive indicates you have the infection. When left undiagnosed and untreated for a long time, it can develop into acquired immunodeficiency syndrome (AIDS)
3. Gonorrhea: Caused by the bacterium Neisseria gonorrhoeae, Gonorrhea is an STI that usually targets warm and moist parts of the body like anus, vagina, and parts of the female reproductive tract like the uterus, cervix, and fallopian tubes.
4. Genital Herpes: This STI causes painful, fluid-filled blisters called herpetic sores, which can burst and ooze pus. Genital herpes can be broadly divided into two categories: HSV-1 and HSV-2.