Sexually transmitted infections (STIs), formerly called sexually transmitted diseases (STDs), are diseases that primarily spread through sexual contact. STIs can be bacterial, such as chlamydia, gonorrhea, and syphilis, or viral, including herpes, HIV, and HPV. Transmission may involve body fluids (blood, saliva, semen, vaginal secretions) or direct skin-to-skin contact. While abstinence is the only way to prevent STIs altogether, knowing the risk factors for transmission can help you protect yourself if you are sexually active.

Frequently Asked Questions

  • Do STIs go away?

    Most sexually transmitted infections (STIs) do not go away on their own without treatment. Bacterial STIs, such as syphilis, chlamydia, and gonorrhea, require treatment with antibiotics to clear. Viral STIs, such as herpes and HIV, are treated with antiviral medications to address symptoms, prevent recurrent outbreaks, and halt disease progression.

  • How do STIs start?

    STIs are infections that are spread through intimate contact including vaginal, oral, or anal sex and foreplay. Some STIs are spread through body fluids including blood, saliva, semen, and vaginal secretions, while others are spread through skin-to-skin contact. STIs can produce obvious symptoms such as genital itching, discharge, or sores, however, people can have an STI with no symptoms.

  • How often should you get tested for STIs?

    All sexually active men and women should be tested for STIs from time to time, but how often depends on your lifestyle. People who have multiple sex partners, sexually active gay and bisexual men, and women under 25 should be tested annually. STI testing is recommended for all pregnant women. In addition, all sexually active people from ages 13 to 64 should be tested for HIV at least once.

  • How can STIs be prevented?

    The only sure way to avoid getting an STI is to abstain from all intimate contact. For most people, that isn’t practical, but fortunately, STIs are largely preventable. Consistent and correct use of condoms helps, but they are not equally effective for all infections. Understanding how STIs are spread and taking appropriate precautions reduces the risk of STI transmission.

  • How much does it cost to get tested for STIs?

    The cost of testing for STIs depends on a few factors. Under the Affordable Care Act, some STI tests fall under preventive care and must be covered by insurance free of charge under certain circumstances. For example, sexually active women under 25 get free preventive screenings for chlamydia and gonorrhea each year, and HIV and syphilis screenings are free for all men and women.

  • What STIs are not curable?

    Some sexually transmitted diseases (STIs) are easily treatable, while others are not. Bacterial STIs can be cleared with antibacterial treatment, but viral STIs are more difficult to treat. Currently, hepatitis B, herpes simplex virus (HSV), human immunodeficiency virus (HIV), and human papillomavirus (HPV) are incurable. Antiviral medications are used to treat the symptoms or halt the progression of these diseases, but there is no cure.

Key Terms

Page Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevent. How you can prevent sexually transmitted diseases. Updated March 30, 2020.

Additional Reading