Syphilis is a sexually transmitted infection (STI) syphilis is caused by bacteria known as Treponema pallidum. It is not as common as some sexually transmitted infections but if left untreated it can cause very serious health problems in both men and women.

How is syphilis passed one?

Syphilis can be passed on without knowing you have the infection because symptoms can be mild and unrecognisable.

Syphilis can be passed from one person to another during sex and by direct skin contact with someone who has syphilis sores or a syphilis rash.
It can be passed on before symptoms are noticeable, or after they’ve disappeared.
The infection can spread if you have vaginal, anal or oral sex, or share sex toys. Using a condom correctly will reduce your chance of getting or passing on syphilis.
Syphilis can also be transmitted by blood transfusion and sharing needles.

It is also possible for a pregnant woman to pass the infection to her unborn baby. This is known as congenital syphilis.

You cannot catch syphilis from kissing, hugging, sharing baths or towels, swimming pools, toilet seats, sharing cups, plates or cutlery


To diagnose syphilis, you'll have a:

  • Physical examination – you will be asked to examine your genitals (and inside the vagina for women) or other parts of your body to look for growths or rashes that may be caused by syphilis.

  • Blood test – this can show whether you have syphilis or have had it in the past; repeating the test a few weeks later may be recommended if it's negative, in case it was too early to give an accurate result.

  • Swab test – a swab is used to take a small sample of fluid from any sores, so it can be checked for syphilis.



First and second stage syphilis is treated using a single antibiotic injection or a course of injections or by taking antibiotic tablets or capsules. Penicillin is the most common treatment for syphilis, but there are several different antibiotics that can be used.

Treatment usually lasts around 10–14 days but sometimes longer. If complications have occurred you may also need other treatment.
If there is a high chance of you having the infection, treatment may be started before the results of the test are back. You will usually be given treatment if any sexual partner has syphilis.


Without proper treatment the infection can spread to other parts of the body causing serious, long-term complications.
Left untreated, syphilis may start to cause very serious damage to the heart, brain, eyes, other internal organs, bones and nervous system. This damage could lead to death.