Syphilis is a bacterial infection that spreads through vaginal, anal and oral sex. It can also be passed from a pregnant person to their baby. Syphilis can spread through kissing if there are syphilis sores in the mouth or on the lips.

If left untreated, syphilis can damage your heart, brain and nervous system, and eventually lead to death. Having syphilis also makes it more likely to get or spread HIV.


Condoms and dental dams can prevent the spread of syphilis, but only if they cover the sore. Having multiple partners increases your risk of getting sexually transmitted infections (STIs), including syphilis.

Taking the medication doxycycline after sex can prevent STIs, including chlamydia, gonorrhea and syphilis. Taking doxycycline to prevent STIs is called Doxy PEP. Doxy PEP works best within 24 hours of sex.


Most people with syphilis do not notice any symptoms. Symptoms include:

  • Painless, open sores called chancres. These can occur on skin that is exposed during sex (penis, vagina, genitals, anus or mouth).
  • Rash, especially on the palms of the hands or soles of the feet.
  • Patchy hair loss.
  • Fever.
  • Swollen lymph glands.
  • Weight loss.
  • Muscle aches.
  • Fatigue.

Symptoms eventually disappear with or without treatment. Without treatment, the infection stays in the body and can be harmful.


Your health care provider will test for syphilis with a blood sample.


An injection of antibiotics is the best treatment for syphilis. Your health care provider will give you at least one injection (sometimes up to three injections). The full treatment is needed to clear the infection.

You should be retested after three months to make sure that the infection has cleared.

Sex Partners

Your sex partner(s) also need to be treated so that they do not develop serious health problems, re-infect you or pass the infection on to others. You should tell all of your sex partners from the previous three to 12 months about your infection so that they can see a health care provider. Your health care provider will help you determine which partners you should contact.

Syphilis in Pregnancy

All pregnant people should be tested for syphilis and other STIs, including HIV, as early as possible in pregnancy. A pregnant parent with syphilis can pass the infection to their baby during pregnancy. This is called congenital syphilis. Congenital syphilis can cause:

  • Stillbirth.
  • Premature birth.
  • Low birth weight.
  • Death shortly after birth.

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