Contrary to what many people believe, oral sex can cause sexually transmitted infections. The possibility of contracting some STIs such as genital herpes and gonorrhea through oral sex is higher than contracting HIV through the same medium. According to the World Health Organization (WHO), one million new STIs infections are acquired each year.

The primary reason that makes it possible to contract STIs through oral sex is that oral sex involves close contact and exchange of bodily fluids. The rate at which an STI spreads depends on the type of the specific STI and the type of the fluid involved.

Genital herpes is a viral infection that is transmitted through vaginal, oral, or anal contact with an individual who has the virus. The infection is manifested through blister-like sores around the sex organs. One can spread the herpes infection to the sex organs of their sexual partners through oral sex. Herpes is not treatable, but proper medication can manage the symptoms.

Gonorrhea is caused by bacteria and is highly contagious. Besides being transmitted through vaginal and oral sex, the infection can be transmitted orally from a person with the bacteria. Symptoms of the STI may include genital discharge, burning during urination, and bleeding between periods. Gonorrhea is treatable, but if untreated it can cause pelvic inflammatory disease in women.

Syphilis is a bacterial infection that is spread through a wide range of sexual practices including vaginal, penile, oral sex, or skin contact with someone with syphilis sores. Symptoms of syphilis include blister-like sores, rashes, and for those who acquire it through oral sex, the symptoms include sores in near mouths and genitals. Syphilis is treatable, but failure to treat it on time may result in dementia and heart and brain problems.