More than 20 million people are infected with sexually transmitted diseases each year. Here's a break down of the most common STDs state by state:

Chlamydia is the most common STD in the U.S., according to the Centers for Disease Control and Prevention. Most people who have chlamydia have no symptoms. It can damage a woman's reproductive system, making it difficult for her to get pregnant.

Gonorrhea can cause infections in the genitals, rectum and throat, but many people who are infected don't have symptoms.

Syphilis often begins with one or more painless sores on the genitalia, usually followed by a rash. If left untreated, the disease can destroy the central nervous system and severely damage organs.

For more information, visit the Centers for Disease Control and Prevention website.