HIV/AIDS 

HIV = Human Immunodeficiency Virus

AIDS = Auto Immune Deficiency Syndrome

HIV is caused by a virus that attacks a person's immune system. If it is not diagnosed and treated at the earliest chance, it can progress to AIDS and result in various severe complications and death.

Chlamydia

Chlamydia is caused by the bacterium called Chlamydia trachomatis and it can infect both men and women. The majority of Chlamydia symptoms are mild, and they often are not noticed that easily.

Syphilis

Syphilis is caused by the bacterium known as Treponema pallidum. It is made up of different stages that feature various signs, symptoms, and complications. The first symptom of Syphilis is a painless open sore called chancre, which may appear around or in the genital region, mouth, or anus.

Gonorrhea 

Also known as "The Clap", gonorrhea is caused by the bacterium known as Neisseria gonorrhoeae. It is transmitted from one person to another through vaginal, anal and oral sex.