Syphilis is a bacterial infection that's usually caught by having sex with someone who's infected.

It's important to get tested and treated as soon as possible if you think you might have syphilis, as it can cause serious problems if it's left untreated.

Syphilis is curable and easy to treat with the antibiotic penicillin.

You can catch syphilis more than once, even if you have been treated for it before.

Symptoms of syphilis

The symptoms of syphilis are not always obvious and may eventually disappear, but you'll remain infected unless you get treated.

Some people with syphilis have no symptoms.

Symptoms can include:

  • small, painless sores or ulcers that typically appear on the penis, vagina, or around the anus, but can occur in other places such as the mouth 
  • a blotchy red rash that often affects the palms of the hands or soles of the feet
  • small skin growths (similar to genital warts) that may develop on the vulva in women or around the bottom (anus) in both men and women
  • white patches in the mouth
  • tiredness, headaches, joint pains, a high temperature (fever) and swollen glands in your neck, groin or armpits

If syphilis is not treated there is a risk of damage to the nervous system (the brain, spinal cord and nerves) as well as the heart. These complications may take many years to develop and happen very rarely in this country because the treatment works so well.

What to do if you think you have syphilis

You should get tested as soon as possible if you're worried you could have syphilis.

This is because:

  • syphilis will not normally go away on its own
  • getting tested is the only way to find out if you have it
  • the medicines used to treat syphilis are only available on prescription – you cannot buy them yourself
  • treatment can help reduce the risk of spreading the infection to others and serious problems developing later on

The best place to get tested is a sexual health clinic.

The test for syphilis usually involves a blood test and removing a sample of fluid from any sores using a swab (similar to a cotton bud).

Treatment for syphilis

Syphilis is usually treated with either:

  • an injection of antibiotics into your buttocks – most people will only need 1 dose, although 3 injections given at weekly intervals may be recommended if you have had syphilis for a long time
  • a course of antibiotics tablets if you cannot have the injection – this will usually last 2 or 4 weeks, depending on how long you have had syphilis 

You should avoid any kind of sexual activity or close sexual contact with another person until at least 2 weeks after your treatment finishes.

How syphilis is spread

Syphilis is passed on:

  • through unprotected vaginal, anal or oral sex with someone who has syphilis
  • by touching ulcers or weeping rashes in someone who has syphilis
  • through blood transfusions, although this is very rare in the UK as donations are tested for syphilis
  • from an infected mother to her unborn baby

Syphilis cannot be caught by hugging, sharing baths or towels, from swimming pools, toilet seats or sharing cups, plates or cutlery

Can syphilis be caught again?

Yes. Having syphilis once gives no protection in future. To prevent this make sure that your partner has been treated before having sex with them again. Protect yourself with new partners by using a condom for all anal, oral and vaginal sex. Ensure that both you and a new partner have a sexual health screen before any unprotected sex (sex without a condom).

Preventing syphilis

Syphilis cannot always be prevented, but if you're sexually active you can reduce your risk by practising safer sex:

  • use a male condom or female condom during vaginal, oral and anal sex
  • use a dental dam (a square of plastic) during oral sex
  • avoid sharing sex toys - if you do share them, wash them and cover them with a condom before each use

These measures can also reduce your risk of catching other sexually transmitted infections (STIs).

If you inject yourself with drugs, do not use other people's needles or share your needles with others.

Syphilis in pregnancy

If a woman becomes infected while she's pregnant, or becomes pregnant when she already has syphilis, it can be very dangerous for her baby if not treated.

Infection in pregnancy can cause miscarriage, stillbirth or a serious infection in the baby (congenital syphilis).

Screening for syphilis during pregnancy is offered to all pregnant women so the infection can be detected and treated before it causes any serious problems.


The symptoms of syphilis are similar for men and women. They're often mild and difficult to recognise, and you may pass on the infection without knowing you have it.

The symptoms tend to change over time and may come and go.

Even if the symptoms do improve, there's still a risk you could pass the infection on or develop serious problems if you don't get treatment.

Early symptoms of syphilis

The first symptoms of syphilis usually develop around 2 or 3 weeks after infection, although they can start later than this.

This stage of the infection is known as "primary syphilis".

  • the main symptom is a small, painless sore or ulcer called a chancre that you might not notice
  • the sore will typically be on the penis, vagina, or around the anus, although it can sometimes appear in the mouth or on the lips, fingers or buttocks
  • most people only have one sore, but some people have several
  • you may also have swollen glands in your neck, groin or armpits

These symptoms usually pass within 2 to 8 weeks. But if the infection isn't treated, it may progress to a second stage.

Later symptoms of syphilis

Further symptoms may develop a few weeks after the initial symptoms have passed. This is known as "secondary syphilis".

Symptoms of secondary syphilis include:

  • a blotchy red rash that can appear anywhere on the body, but often develops on the palms of the hands or soles of the feet
  • small skin growths (similar to genital warts) – on women these often appear on the vulva and for both men and women they may appear around the anus
  • white patches in the mouth
  • flu-like symptoms, such as tiredness, headaches, joint pains and a high temperature (fever)
  • swollen glands
  • occasionally, patchy hair loss

These symptoms usually pass within a few weeks, although they may come and go over several months before they disappear.

You'll still be infected even if you don't have symptoms. This is known as "latent syphilis" and it can last for decades and lead to serious problems if not treated.

It's still possible to pass on the infection during this stage, although this usually only happens within 2 years of becoming infected.

Serious problems if left untreated

Without treatment, a syphilis infection can last for years or decades without causing any symptoms.

Eventually, it can spread to parts of the body such as the brain or nerves and cause serious and potentially life-threatening problems. This is known as "tertiary syphilis".

People with tertiary syphilis may experience:

  • meningitis
  • strokes
  • dementia symptoms
  • loss of co-ordination
  • numbness
  • vision problems or blindness 
  • heart problems

Syphilis is still treatable at this stage, but it's sometimes not possible to reverse any damage that's already been done.


The only way to find out if you have syphilis is to get tested.

Syphilis causes serious problems if left undiagnosed and untreated.

Who should get tested for syphilis

You should get tested for syphilis if:

  • you're worried you might have it
  • a sexual partner has been diagnosed with syphilis
  • you have symptoms of syphilis

It's particularly important to get tested in these cases if you've had sex without a condom (unprotected sex), you have multiple sexual partners, you're a man who has sex with men, or you've had sexually transmitted infections (STIs) in the past.

Where to get a syphilis test

The best place to get tested for syphilis is a sexual health clinic

Find a sexual health clinic.

These clinics are staffed by healthcare professionals with special expertise in STIs. They tend to have easier access to the tests and treatments for syphilis than your local GP surgery.

You can go to your GP if you prefer, although they may refer you to a sexual health clinic if they suspect you might have an STI.

What the test for syphilis involves

You'll be asked about your sexual history and habits, and whether you're experiencing any symptoms.

To diagnose syphilis, you'll usually have a:

  • physical examination - a doctor or nurse will ask 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 (similar to a cotton bud) is used to take a small sample of fluid from any sores, so it can be checked for syphilis

You should also be tested for other STIs, such as chlamydia and gonorrhoea, as it's possible to have more than one STI at a time. Some results may be available the same day, while others may take a week or 2 to come back.

You should avoid having sex or close sexual contact with anyone else until you get your test results.

Screening for syphilis in pregnancy

All pregnant women are offered a blood test to check for syphilis, usually at around 8-12 weeks of pregnancy.

A syphilis infection during pregnancy can be very dangerous for the baby, but the screening test can help ensure it's detected and treated as soon as possible.

The test can be repeated if there's a risk you may have been exposed to syphilis later in your pregnancy.



Syphilis is curable and easy to treat with the antibiotic penicillin, usually by injection into the muscle of your buttock. The number of injections depends on how long you have been infected. If you are allergic to penicillin, you will be given a different antibiotic.

Antibiotics for syphilis

A short course of antibiotics can usually cure syphilis. These are only available on prescription, so you'll need to be tested for syphilis to get them.

The type of treatment you need depends on how long you've had syphilis.

Syphilis that has lasted less than 2 years is usually treated with an injection of penicillin into your buttocks, or a 10-14 day course of antibiotic tablets if you can't have penicillin.

Syphilis that has lasted more than 2 years is usually treated with 3 penicillin injections into your buttocks given at weekly intervals, or a 28 day course of antibiotic tablets if you can't have penicillin.

More serious cases that affect the brain are usually treated with daily penicillin injections given into your buttocks or a vein for 2 weeks, or a 28 day course of antibiotic tablets if you can't have penicillin.

Follow-up blood tests will be recommended once treatment finishes to check that it has worked.

Side effects of treatment

You may experience some side effects shortly after treatment.

Around 2 in every 5 people experience short-lived flu-like symptoms, such as:

  • a high temperature (fever)
  • headaches
  • muscle and joint pain

These symptoms usually only last 24 hours and can often be treated with paracetamol. Get advice from your doctor if they're severe or don't settle down.

There's also a risk of having an allergic reaction shortly after a penicillin injection. You'll be monitored after treatment to check for this and will be treated if it occurs.

Avoiding sex during treatment

Avoid any kind of sexual activity or close sexual contact with another person until at least 2 weeks after your treatment finishes.

This includes vaginal, anal and oral sex, as well as close skin contact.

If you have sex during treatment, you could become infected again or pass the infection on to someone else.

Notifying and treating sexual partners

Your current and previous sexual partners should be tested and treated for syphilis as well, as leaving the infection untreated can lead to serious problems.

How far back you need to go depends on how long you had syphilis before it was diagnosed and treated.

You can choose to either notify your previous sexual partners yourself, with support from clinic staff, or the clinic can contact them by letter or phone and advise them to go for a check-up.

If the clinic contacts your previous sexual partners for you, your details will remain totally confidential and no information about you will be given out without your consent.

Treating syphilis during pregnancy

Pregnant women with syphilis can be safely treated with antibiotics.

The treatment you need depends on how long you've had syphilis and how far along in your pregnancy you are.

Pregnant women who've had syphilis for less than 2 years are usually treated with an injection of penicillin into the buttocks (if treated during the first or second trimester) or 2 injections given a week apart (if treated during the third trimester).

Pregnant women who've had syphilis for more than 2 years are usually treated with 3 penicillin injections into the buttocks given at weekly intervals.

A short course of antibiotic tablets may be needed if you can't have penicillin.

The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website
Last Updated: 06/04/2022 15:13:10