Sexually transmitted infections: Common questions

What is a sexually transmitted infection?

A sexually transmitted infection (also called STI, sexually transmitted disease or STD) is an infection that you can get from having unprotected sex (vaginal, anal or oral sex) or intimate physical contact with someone who is infected. Some examples of STIs include gonorrhea, chlamydia and hepatitis B.

Can you get an STI without having sex?

Some STIs can spread in ways other than sex. For example, you can get some STIs, like syphilis and herpes, by having direct contact with body fluids from an infected person. This can happen by genital touching, touching or kissing an infected sore (in the case of syphilis) or by sharing drug needles or other items that come in contact with body fluids from an infected person.

How do you know if you have an STI?

Many people with STIs don’t know they’re infected because they often have no signs or symptoms. Common signs and symptoms of STIs include:

  • Flu-like symptoms, including headache and fatigue (feeling very tired)
  • Vaginal discharge or burning, itching, redness or swelling in the vaginal area
  • Belly pain
  • Pain during sex or bleeding after sex or between periods
  • Sores on the mouth or the vaginal, genital or anal areas

What problems can STIs cause?

STIs can cause health problems and, if you’re pregnant, they can affect your baby’s health. Without treatment, STIs can lead to conditions like:

  • Pelvic inflammatory disease (also called PID). This is an infection of a woman’s reproductive organs, including the uterus (also called womb). PID can make it hard for you to get pregnant. During pregnancy, it can lead to problems like ectopic pregnancy.
  • Premature birth. This is birth that happens too early, before 37 weeks of pregnancy. Babies born early are at risk for having health problems at birth and later in life.
  • Birth defects. These are health conditions that are present at birth. They change the shape or function of one or more parts of the body. Birth defects can cause problems in overall health, how the body develops or how the body works.
  • Miscarriage. This is the death of a baby in the womb before 20 weeks of pregnancy.
  • Stillbirth. This is the death of a baby in the womb after 20 weeks of pregnancy.

Having an STI can have serious effects on your baby, which may be seen at birth or may not be discovered until months or years later.

How are STIs treated?

If you’re pregnant or planning to become pregnant, talk to your health care provider about getting tested for STIs. If you find out you have an STI, get treatment right away. Getting treatment can help protect you and your baby during pregnancy and birth.

If you have an STI that’s caused by bacteria, your provider prescribes antibiotics (medicines that kill infections caused by bacteria) to treat it. STIs that are caused by a virus (like HIV, HPV, herpes or hepatitis) can’t be cured with treatment. But treatment can help you manage signs and symptoms.

To learn more about what you can do to protect yourself and your baby from STIs, visit .