From www.cdc.gov -
Sexually transmitted diseases (STDs) affect men and women of all backgrounds and economic levels. In the United States, overall incidence of STDs has increased dramatically in recent years. The CDC estimates that 19 million new infections occur each year, almost half of them among young people ages 15 to 24.
Despite the fact that STDs are extremely widespread and add an estimated $13 billion dollars to the nation's healthcare costs each year, most people in the United States remain unaware of the risk and consequences of all but the most prominent STD—HIV, the virus that causes AIDS.
Many people are aware of the most prominent STD—HIV. However, many other STDs affect millions of men and women each year. Many of these STDs initially cause no symptoms, especially in women. Symptoms, when they do develop, may be confused with those of other diseases that are not transmitted through sexual contact. STDs can still be transmitted person to person even if they do not show symptoms. Also, health problems caused by STDs tend to be more severe for women than for men.