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The Facts About Syphilis

Find out how syphilis affects your sexual health.

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Though once thought to be on the brink of eradication, syphilis is once again becoming more common, making early detection and treatment essential to avoiding serious complications and the further spread of this dangerous infection.

What is syphilis?

Syphilis is a sexually transmitted disease (STD) caused by a corkscrew-shaped bacteria called Treponema pallidum. The disease dates back hundreds of years. It was first recorded in July 1495 in Naples, Italy, and called "the French Disease" because people blamed its spread on French soldiers returning from the battle of Fornovo. Since then, syphilis has been reported to affect individuals in plague-like proportions. Despite its recent resurgence, modern medicine provides the benefit of a cure for syphilis, something that wasn't available to societies of yesteryear.

While syphilis can cause visible sores at certain stages of the disease, it remains possible for a person to be unaware of their infection, as early symptoms can be missed or mistaken for other ailments.

Syphilis can survive in the body for decades and go through long periods of inactivity, lying dormant, only to manifest later. Though syphilis is considered an STD, it can also be spread from mother to child during pregnancy, posing the threat of fetal deformities and mortality.

Thus, it's essential to get regularly tested for STDs if you are sexually active, especially if you have sex with multiple partners or an individual who has multiple partners.

How do you get syphilis?

The bacterial syphilis infection first manifests as one or multiple painless sores typically located on the genitals, anus, rectum or mouth. Transmission occurs during sexual activity when an individual's skin or mucous membrane makes contact with these sores. A person can unknowingly infect their sexual partners because the sores are painless and often in easy-to-miss areas.

While most syphilis cases are spread through sexual activity, the disease can be spread congenitally, which means the disease can be passed from mother to fetus during pregnancy or, less commonly, during the newborn's passage through the birth canal itself.

Demographics and risks

The Centers for Disease Control and Prevention (CDC) reports that in 2020 there were 133,945 documented cases of syphilis, with 41,655 of those cases being primary or secondary syphilis, the stages at which the disease is most infectious. Documented cases of syphilis are more common among men than women.

National statistics reveal significant disparities in syphilis cases among different demographics, as men who have sex with men are disproportionately represented. Men who have sex with men account for 53 percent of all men with reported cases of primary or secondary syphilis.

In the United States, rates of syphilis are highest in the Southeast, Southwest and West. While cases have risen in most racial and ethnic groups, the greatest climb in cases is among non-Hispanic American Indian/Alaska Native people and non-Hispanic individuals of multiple races, according to CDC statistics.

Syphilis carries the threat of serious complications if left untreated, including a greater risk of contracting human immunodeficiency virus (HIV). According to public health experts, an individual who has syphilis sores is more susceptible to contracting HIV during sexual activity with an HIV-positive person.

Stages of syphilis

Primary- and secondary-stage syphilis account for the greatest number of syphilis cases, though a lack of STD testing in conjunction with unnoticed symptoms can make it possible for the disease to progress to later stages, leading to more serious complications.

Here are the different stages of syphilis:

  • Primary syphilis. During this stage, one or more small sores called chancres appear where the infection entered the body. The chancre appears about three weeks after exposure and usually clears up on its own within three to six weeks. In many cases, these small sores go unnoticed because they don't normally cause pain and are often in easy-to-miss locations, such as inside the vagina or rectum.
  • Secondary syphilis. For some people, this is the stage at which a syphilis rash appears on the trunk of the body, eventually spreading everywhere else, including the palms of the hands and soles of the feet. In some cases, wart-like sores appear in the mouth or genital region. Individuals with secondary syphilis may also begin to lose their hair, have muscle aches and develop a fever, a sore throat and swelling of the lymph nodes. Symptoms have been known to last a few weeks and come and go for up to a year if left untreated.
  • Latent syphilis. When secondary syphilis goes untreated, it eventually transitions into a latent stage, during which signs and symptoms disappear and may never come back. However, in other cases, the latent stage—which can last for many years—may progress to the tertiary stage.
  • Tertiary syphilis. At this stage, individuals develop complications including damage to the brain, nerves, heart, eyes, liver, blood vessels, joints and bones. An estimated 15 percent to 30 percent of people with untreated syphilis develop tertiary syphilis.

Neurosyphilis, which damages the brain, nervous system and eyes, can develop at any stage of the disease.

Symptoms and diagnosis

Syphilis has a broad array of symptoms, all of which vary depending on the stage of the disease. In some cases, the stages may overlap, and each individual may not experience symptoms in the same order. It's also possible for symptoms to go unnoticed for years.

Here are some symptoms that can be experienced in various stages of syphilis:

  • Development of one or many small, painless sores at the entry point of the infection (typically the genital region, rectum or anus)
  • Syphilis rash on the torso that spreads to the rest of the body, including palms of hands and soles of feet
  • Loss of hair
  • Muscle aches
  • Sore throat
  • Swollen lymph nodes
  • Fever
  • Damage to the brain, eyes, nerves, heart, blood vessels, liver, bones and joints

Syphilis is diagnosed with a blood test. In some cases, cerebrospinal fluid can be tested to determine whether nervous system complications are a result of syphilis.

Treatment and prevention

Syphilis that is detected and treated in the primary and secondary stages is easily cured with antibiotics. Penicillin is used as a treatment for all stages of the disease, though other antibiotics or penicillin desensitization may be necessary when an individual has a penicillin allergy. Infants born with congenital syphilis can also be treated with antibiotics.

Practicing safer sex or abstaining from sex altogether are the only ways to ensure you don't contract syphilis. If you're sexually active, get tested regularly and have sex only with partners who also practice safer sex and undergo regular testing to help decrease your risk of contracting syphilis.

Can syphilis be cured?

If you detect and treat syphilis in its early stages, you can be cured of the disease by using penicillin. Untreated syphilis can eventually cause damage to many different organs and systems in the body.

While the disease can be cured, the damage it causes in the later stages is irreversible.

Syphilis and pregnancy

The symptoms and stages of syphilis are the same for people who are pregnant.

Since syphilis can be passed from parent to child during pregnancy and birth, and lead to severe fetal abnormalities and fatality, some states require obstetricians to screen every pregnant person for the disease at the beginning of their pregnancy.

Though medications are sometimes avoided during the first trimester, the threat syphilis poses to the fetus is great enough that medical experts typically recommend treatment immediately. Currently, long-acting benzathine penicillin G is the only syphilis treatment recommended for people who are pregnant. The risk of congenital syphilis can be reduced by about 97 percent when syphilis is treated during pregnancy.

Long-term effects on sexual health

After completing syphilis treatment and getting the all-clear from your doctor, you can resume sexual activity. Going forward, you should practice safer sex and get tested regularly to ensure you don't get reinfected in the future.

Though syphilis itself doesn't continue to impede sexual health once treated, people who have syphilis are at greater risk of contracting HIV.

If an individual contracts HIV while infected with syphilis, there will be longer-term sexual health effects to be considered on an ongoing basis.


When an individual is treated for syphilis, they need to undergo blood tests and exams periodically to ensure their body is responding to the level of penicillin administered during treatment. Sexual activity should be avoided until your doctor can confirm with a blood test that the disease is cured. You also should get tested for HIV because of the increased risk to people infected with syphilis.

Some people may experience the Jarisch-Herxheimer reaction within the first day of treatment. The reaction typically consists of fever, nausea, body aches, chills and headache, but usually dissipates within a day or two.


Who is most at risk for syphilis?

Men are at a greater risk for syphilis than women, especially men who have sex with men. They account for 53 percent of all men with reported cases of primary or secondary syphilis.

How is syphilis diagnosed?

Syphilis is diagnosed with a blood test. In cases where there are complications with the nervous system, cerebrospinal fluid may be used for diagnosing syphilis.

What does syphilis do to a person?

The first symptoms of syphilis are sores in the genital region, rectum, anus or mouth, followed by rashes that may develop and spread over the entire body. When left untreated, syphilis can damage the brain, eyes, nerves, heart, blood vessels, liver, bones and joints.