Sexually transmitted diseases (STDs), also known as sexually transmitted infections or STIs, are very common. Millions of new infections occur every year in the United States.
STDs are passed from one person to another through sexual activity including vaginal, oral, and anal sex. They can also be passed from one person to another through intimate physical contact, such as heavy petting, though this is not very common.
STDs don’t always cause symptoms or may only cause mild symptoms, so it is possible to have an infection and not know it. That is why it is important to get tested if you are having sex. If you are diagnosed with an STD, know that all can be treated with medicine and some can be cured entirely.