Many people think of syphilis as a disease of the past – something confined to history books rather than a present-day concern. The data tells a very different story. In 2025, more than 8000 cases of infectious syphilis were diagnosed in England. Despite these numbers, many people know surprisingly little about the infection. Here, we answer some of the most common questions.
What is syphilis?
Syphilis is a sexually transmitted infection (STI) caused by bacteria. It is preventable and, if caught early, is straightforward to cure. Left untreated, however, it can cause serious and potentially life-threatening health problems.
What are the symptoms?
Syphilis is sometimes called ‘the great imitator’ because its symptoms can be mild, hard to notice, or can mimic other conditions. Symptoms typically progress through stages and in the later stages they are more likely to be seen outside of sexual health services.
Early stages
- the most common sign is a sore (ulcer), at the site where the infection entered the body – on the genitals, around the anus, or inside the mouth
- the sore can be painless and may be hidden inside the body; many people don’t notice it.
- even without treatment, the sore usually heals on its own – but the infection remains
Later stages
Symptoms can include:
- a rash on parts of the body including the palms of the hands and soles of the feet
- flu-like symptoms such as fever, headaches and tiredness
- patchy hair loss
- white patches in the mouth
If syphilis is not treated, it can eventually cause serious damage to the heart, brain, nerves and other organs – sometimes many years after the initial infection.
How is syphilis spread?
Syphilis can be passed on during the earlier stages of infection, which can last up to 2 years. The most common route is through unprotected vaginal, anal or oral sex with someone who has the infection. Many people do not know they are infected, as symptoms can be absent or go unnoticed. Syphilis can also be passed from a pregnant person to their unborn baby – known as congenital syphilis – which can cause stillbirth, neonatal death, or lifelong disability.
Who is most at risk?
Syphilis can affect anyone who is sexually active, but cases in England are currently most concentrated among gay, bisexual and other men who have sex with men. However, diagnoses among heterosexual men and women have been rising sharply over the past decade, and cases are increasingly being seen across a wider range of communities and geographic areas.
How can I prevent it?
- using condoms consistently for vaginal, anal and oral sex significantly reduces the risk of transmission
- getting tested regularly – especially before sex with a new partner
- if you or your recent sexual partners are diagnosed, it is essential that treatment is completed to prevent re-infection
- people at higher risk may also be able to access doxycycline post-exposure prophylaxis (doxyPEP), a medication that can reduce the risk of bacterial STIs including syphilis; speak to a sexual health clinic for advice
How do I get tested and treated?
Testing is free on the NHS and can be done at a sexual health clinic or via a home self-sampling kit ordered online.
Syphilis is diagnosed using a blood test or a swab from a sore.
Treatment is straightforward – usually a single antibiotic injection or a short course of tablets, although a course of injections may be necessary in some cases. After treatment, a follow-up test at 6 and 12 weeks confirms the infection has cleared.
Anyone diagnosed with syphilis should ensure their recent sexual partners are also tested, which can be arranged confidentially through a clinic.
What is UKHSA doing about syphilis?
The UK Health Security Agency (UKHSA) monitors syphilis trends across England, providing national and local surveillance data to help health services target their responses effectively.
UKHSA has published a Syphilis Response Plan structured around 4 pillars:
- prevention
- testing
- treatment
- elimination of congenital syphilis
UKHSA works with NHS services, local authorities, academic partners and community organisations to improve awareness and support local teams with outbreak responses and care pathway improvements. A particular priority is eliminating congenital syphilis, an ambition aligned with WHO targets.
Where can I get help?
If you think you may have syphilis, or if a recent partner has been diagnosed, contact your local sexual health clinic or GP as soon as possible. You can find your nearest sexual health service on the NHS website. STI testing is free, confidential, and available to everyone, no matter your age, gender, ethnicity or sexuality.
