At a glance

  • Syphilis is a sexually transmitted infection (STI).
  • It is caused by bacteria.
  • Sometimes there are no noticeable symptoms, but it may go through various stages – starting with a sore, and later followed by symptoms like fever and a rash.
  • There may be long phases without symptoms in between.
  • Syphilis can be treated effectively with antibiotics.
  • If it's not detected and treated, it can seriously damage internal organs and the nervous system over the long term.


Photo of a man

Syphilis is caused by . It is a sexually transmitted (STI) – like gonorrhea, chlamydia and trichomoniasis.

At the beginning of the , there is typically a single, painless sore (also known as a chancre) that heals on its own. Depending on where the got into the body, the sore forms on the penis, vagina, anus (bottom), lips or in the mouth.

If left untreated, syphilis goes through various stages that may include a fever, sore throat, headache and rash. In the late stage, it can damage the aorta (main artery), the spinal cord or the brain and cause serious complications. Sometimes people have no symptoms for years between the stages. And many never have any symptoms at all. Then the disease may remain undetected and be unknowingly passed on to others.

Syphilis can be treated effectively with . A long-acting penicillin drug is usually given as an injection. Other types of can be used as well, though.


If syphilis causes symptoms, various different kinds may occur, depending on the stage of the disease and which part of the body was first infected.

If the were passed on during vaginal sex, a sore usually forms on the outer sexual organs first (known as the primary stage). If the was passed on during anal or oral sex, the sore can form around the anus (bottom), lips or in the mouth. The nearby lymph nodes often swell up at the same time. The sore is painless, so it sometimes goes unnoticed. It is very contagious because it has a lot of in it. The sore heals on its own, but may leave a small scar.

Illustration: A sore (chancre) in the primary stage of syphilis

Several weeks or months may pass until other symptoms occur: Then you get a fever and your lymph nodes become swollen again – but this time in other places, like the armpits. A headache and joint pain are also typical.

Many people get a skin rash too, with reddish-brown patches or little bumps. The rash isn’t usually itchy. It can develop on any part of the body, disappear again, and then come back after a while. It may be different when it returns – for instance, only red patches on the palms of the hands and soles of the feet.

Illustration: Possible syphilis rashes

There might also be wart-like bumps in the genital area that contain a lot of and are therefore highly contagious.

If the disease remains untreated, the symptoms often go away for a long time, but the stay in your body and can cause symptoms again at a later stage.

Causes and risk factors

Syphilis is caused by bacteria known as Treponema pallidum. These only infect humans and are mainly passed on during sex – through small cuts in the skin, or contact with infected mucous membranes, blood or wound fluid.

The risk of getting a sexually transmitted is especially high if you often have sex with different partners and do not use a condom.

As the disease progresses, the spread throughout the whole body in the bloodstream. So syphilis can also be passed on between people who inject drugs using shared needles. Syphilis can only survive for a short time outside the body. Infection through objects like sauna benches, toilets or shared towels is unlikely. If shared sex toys are used during sex, they should be cleaned before passing them on to others, and a fresh condom should be put on a dildo before use, for instance.

Women might infect unborn children with syphilis when they're pregnant: The can be passed on through the umbilical cord.


In Germany, every case of syphilis is reported to the Robert Koch Institute anonymously (without giving the person’s name). Because of this obligation to report cases, the prevalence of syphilis can be estimated quite accurately in Germany: Every year about 9 out of 100,000 people become infected. But that's an average. More infections are registered in cities than in rural areas. Syphilis is also much more common in men than in women – especially in men who have sex with men.

The disease is usually diagnosed between the ages of 20 and 40 in women, and between the ages of 25 and 50 in men. The number of infections has increased in recent years. That might be because more people are becoming infected, and infections are being detected more frequently.

Some people are regularly tested for syphilis – for instance, if they are taking medication to prevent HIV (known as HIV pre-exposure prophylaxis). You can only use that medication if you agree to be tested for HIV and other sexually transmitted diseases every three months. But it's not clear whether the increased rates are a result of more frequent testing or whether there are other reasons.


Untreated syphilis can go through several stages with different symptoms:

  • About three weeks after becoming infected, the first symptoms appear (primary stage).
  • They go away on their own within a few weeks, but the stay in the body.
  • After a few weeks or months, the will have spread through the body and may cause other symptoms, including things like a fever, headaches, joint pain and skin rashes.
  • These symptoms then come and go in waves over months or years, with symptom-free phases in between. The symptoms on the skin may change over time.

The symptom-free phases (called latent phases) can last for years or decades at a time. If syphilis is left untreated, about one third of those affected will develop the late stage (tertiary stage) of the disease after a while, with damage to the nervous system and internal organs, as well as other complications. People are usually no longer contagious by this stage.

About half of people who have a syphilis never notice any symptoms at all, though.

Syphilis can, and should, be treated at any stage of the disease – regardless of whether it causes any symptoms. But recovering from the illness doesn't mean you're immune: You can get infected again.


People rarely reach the late stage of the nowadays. Typical late complications include nerve damage (also called neurosyphilis) that can cause severe pain, paralysis or dementia. Gummas may also develop in various places in the body. These are growth-like areas of that destroy the tissue. They can sometimes be seen on the skin as open sores. They often also attack the bones or joints. Syphilis-related inflammations can damage blood vessels as well. That might lead to potentially life-threatening internal bleeding.

If a woman becomes infected with syphilis during pregnancy or was already infected before, she might pass the on to her unborn child. Left untreated, the can lead to a miscarriage – or to serious complications in the newborn child, similar to late-stage complications in adults. Known as congenital syphilis, this is very rare in Germany and other countries.

Illustration: Possible late complications of syphilis


A syphilis test can be done to quickly determine whether or not you have the disease. A blood sample is usually taken for this test. In Germany, you can have it done at your family doctor's practice or at a dermatology, gynecology or urology practice. Local health departments and sexual health clinics also offer the test – anonymously, if you prefer.

Sometimes other diagnostic tests are done too. The can also be detected in fluid taken from the chancre sore in the primary stage of syphilis. Imaging techniques (like x-rays or CT scans) might be done or a cerebrospinal fluid sample taken (spinal tap) to detect complications or see whether the late stage of the disease has already been reached.


Condoms and femidoms (condoms for women) reduce the risk of getting syphilis. But they do not provide complete protection because they only cover the penis or the vagina and part of the vulva (outer part of women's genitals). Syphilis can be passed on through intensive skin contact in the entire genital area, though. The typical sores are particularly contagious. If a sore develops in the mouth, syphilis can be passed on through oral sex or intensive kissing too.

Early testing and treatment prevent possible late complications and stop the from being passed on to others. It is also advisable for women to have a syphilis test early on in pregnancy, to prevent complications in the child.

There is no vaccine for syphilis.


Syphilis can be treated effectively with . Usually, a long-acting type of penicillin is injected into the buttock muscles. Its effect lasts long enough to kill all the syphilis in the body. People who are allergic to penicillin, or can't have injections into the muscle, can use other . Other options may then include taking a two-week course of antibiotic tablets or having a daily drip over ten days.

Antibiotics are still used even if complications have already developed. But the treatment then takes longer than in the early stages of the .

Further information

The German Federal Centre for Health Education (BZgA) has information about sexually transmitted infections like syphilis on its website This includes practical prevention tips, a telephone hotline and online advice.

You can contact your local sexual health clinic for more information and advice. The German AIDS Service Organization (Deutsche Aidshilfe) also offers an online service to help people in Germany find the closest place to be tested for syphilis or other sexually transmitted infections.

Deutsche STI-Gesellschaft (DSTIG). Diagnostik und Therapie der Syphilis (S2k-Leitlinie). AWMF-Registernr.: 059-002. 2021.

Deutsche STI-Gesellschaft (DSTIG). Sexuell übertragbare Infektionen (STI): Beratung, Diagnostik und Therapie (S2k-Leitlinie). AWMF-Registernr.: 059-006. 2018.

Nenoff P, Manos A, Ehrhard I et al. Nichtvirale sexuell übertragene Infektionen – Epidemiologie, Klinik, Labordiagnostik und Therapie. Teil 3: Treponemen, Gardnerella und Trichomonaden. Hautarzt 2017; 68(2): 136-148.

Robert Koch-Institut (RKI). RKI-Ratgeber Syphilis. 2020.

Robert Koch-Institut (RKI). Syphilis in Deutschland im Jahr 2019 – Neuer Höchststand von Infektionen. Epidemiologisches Bulletin 2020; 49: 3.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Created on July 17, 2023

Next planned update: 2026


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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