| STI | Symptoms | Estimated Annual Prevalence of New Infections in the U.S. |
| Chlamydia | Women often have no symptoms; men can experience discharge from penis, burning when urinating, and pain/swelling of the testicles. | 2.86 million |
| Gonorrhea | No symptoms may be present in men or women. Men can experience burning when urinating; white, yellow, or green discharge. Women can experience pain/burning when urinating, or vaginal discharge. | 820,000 |
| Herpes | Blisters on the genitals, rectum or mouth; painful sores after blisters break; fever, body aches, and swollen glands can occur. | 776,000 |
| Human papillomavirus (HPV) | Genital warts; certain cancers; warts growing in the throat. | 14.1 million |
| Syphilis | Firm, round sores that first appear where the infection enters the body and can then spread to other parts of the body. | 55,400 |
| Sexually transmitted infections (STIs) are extremely common. HPV, for example, is so widespread that nearly all sexually active people are infected at one time or another. |
| SOURCES: CDC (2012 A, B, C, D, F, 2013). |