First the Facts

  • Syphilis is a sexually transmitted infection (STI).
  • Syphilis is caused by infection with a bacterium called Treponema pallidum.
  • There are different stages of infection, usually starting with a painless ulcer on your genitals. If untreated the infection can spread to other parts of the body with the potential for infected individuals to become seriously unwell.

How Is Syphilis Transmitted?

  • By having unprotected sexual contact with someone who has the infection. This can include vaginal, anal or oral sex, or by sharing sex toys.
  • This person might not have any symptoms and might not know they have syphilis.
  • Anyone can have syphilis – you do not need to have had a lot of partners.
  • Syphilis can also be passed through the blood, usually by sharing needles. Getting syphilis through a blood transfusion is very rare in the UK as all donations are screened for syphilis.
  • Syphilis can be passed from mother to baby during pregnancy. This is called congenital syphilis.
  • You cannot get syphilis through the saliva (e.g. kissing or sharing cutlery), hugging, toilet seats, or sharing towels.

How Will I Know If I Have Syphilis?

The best way to find out is to get a test.
The symptoms can be subtle and may be missed, with some stages of syphilis showing no symptoms.

Syphilis generally develops in stages, which can occur separately or together, and these are grouped into early (primary, secondary and early latent) and late (late latent and tertiary) stages.

StagePossible symptoms
Primary syphilis
• Initially an ulcer (a ‘chancre’) forms. This can be painful or painless.
• This is most commonly located on the genitals (foreskin, penis, scrotum, or vulva, vagina, cervix), or around the anus, but can occur anywhere on the body.
• These ulcers are very infectious and can last several weeks.
Secondary syphilis
• This usually occurs if syphilis is untreated, around 4–10 weeks after any ulcers have appeared.
• This stage is also infectious.
• Many different symptoms can occur and can come and go.
• Symptoms include: rash, warty-type growths on the genitals or anus (sometimes mistaken for genital warts), swollen glands, generally feeling tired and unwell, or sore throat.
Latent syphilis
• Latent means ‘hidden’. This occurs after the symptoms of primary and secondary syphilis have gone away.
• It is divided into early (less than 2 years from infection) and late (more than 2 years from infection).
• A person may still be infectious during this phase.
Tertiary syphilis
• If untreated for many years, syphilis may lead to damage to the heart, brain, bones and nervous system.
• Late syphilis is rare in the UK.

How Can I Protect Myself?

  • The use of condoms for vaginal and anal sex and condoms or dental dams for oral sex can help to prevent transmission.
  • Avoid sharing sex toys or wash between uses.
  • Don’t share needles if injecting drugs.
  • Get tested (see below).

Where and When Can I Get a Test?

The test for syphilis is a blood test, either via ‘venepuncture’ (a small needle into the arm) or a finger prick test you can do yourself.

  • You should get a test if:
    • You have a new partner
    • You have had unprotected sex
    • A partner has told you they have syphilis
    • You have any of the symptoms listed above
    • You have another STI
    • In the UK, all pregnant mothers are routinely screened during antenatal care
  • You can get a test at:
    • A sexual health or genitourinary medicine (GUM) clinic
    • Some young person’s / contraception clinics
    • Some GP surgeries

 If you have symptoms, you should attend a sexual health or GUM clinic.

 It can take up to 3 months after sexual contact to show an infection; however, you should still get a test as soon as possible. If this is negative, you may be advised to take a further test.

 What Happens If I Have Syphilis?

  • You will receive treatment with a penicillin-based antibiotic.
  • Treatment early on is very effective. Treatment for tertiary syphilis will not reverse any damage caused to the body (see symptoms table).
  • Some people experience a reaction to the first treatment, causing a temperature, muscle and joint pains and a headache, usually lasting 12–24 hours. This is not dangerous and is caused by the bacteria breaking down.
  • You will also be offered testing for other STIs if you have not already had this.
  • You must tell your partner, as they will need to be tested and treated as well.
  • Do not have sex until at least 2 weeks after completing treatment, as you can risk passing the infection on. A condom can split, so it is better not to have sex at all for this time.
  • You will need to be re-tested to check your response to treatment.

What If I Don’t Get Treated for Syphilis?

  • If syphilis is not treated early, it can progress to the later stages, which can be more difficult to treat. Tertiary syphilis can cause irreversible damage to the brain, heart, bone and nervous system.
  • You could pass syphilis on to other people.
  • If you have syphilis and have sex with someone who is HIV-positive, you are more likely to contract HIV from this person than if you did not have syphilis.


Written by: Dr Nikki Kersey and Dr Paula Briggs
Last updated: January 2021

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