Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum. It develops in stages and can affect many parts of the body if left untreated — including the brain, heart, and nervous system. But here’s the key: syphilis is curable with antibiotics, especially when caught early.
Syphilis is known as “the great imitator” because its symptoms can look like other illnesses. It often starts with a painless sore and may later cause rashes, swollen glands, or no symptoms at all.
How common is syphilis?
Syphilis has been rising in the U.S. for over a decade. According to the CDC, more than 175,000 cases were reported in 2021, including sharp increases in women and in babies born with syphilis (congenital syphilis). Testing and early treatment are more important than ever.
What Are Symptoms of Syphilis?
Syphilis symptoms vary depending on the stage. There are four main stages: primary, secondary, latent, and tertiary. You can move from one stage to the next if it’s not treated — even without symptoms in between.
Primary syphilis
- A single sore (called a chancre) appears where the bacteria entered the body — usually on the genitals, anus, or mouth
- The sore is painless and firm, and may go unnoticed
- It lasts 3–6 weeks and heals on its own, but the infection remains
Secondary syphilis
- Skin rash, often on the palms of hands or soles of feet
- Rough red or brown spots, sometimes mistaken for acne or allergies
- Fever, sore throat, swollen lymph nodes, fatigue, patchy hair loss
- White patches in the mouth or genital area
Latent syphilis
- No symptoms at all
- Bacteria still live in the body and can cause damage over time
Tertiary syphilis
- Occurs years after infection in people who were never treated
- Can damage the brain, nerves, heart, blood vessels, liver, bones, and joints
- Rare but serious — can be fatal
Neurosyphilis and ocular syphilis
These can happen at any stage:
- Headaches, vision problems, coordination issues, confusion
- Can cause permanent blindness or dementia-like symptoms
What Does Syphilis Look Like?
The classic sign of early syphilis is a painless sore (chancre) at the site of infection. It might be on the vulva, penis, anus, mouth, or even inside the vagina or rectum — making it easy to miss.
The sore:
- Is round, firm, and doesn’t hurt
- Appears 10–90 days after exposure (average is 21 days)
- Lasts about 3–6 weeks, then heals — but the infection stays
In secondary syphilis, you may see:
- A rough, red rash (especially on the palms or soles)
- Flat, moist, wart-like lesions around the genitals or anus
- White patches in the mouth
Later stages don’t show anything on the skin — but damage may still be happening inside the body.
How Is Syphilis Transmitted?
Syphilis spreads through direct contact with a syphilitic sore — usually during vaginal, anal, or oral sex. It can also spread during deep kissing if there’s a sore in the mouth.
You can get syphilis from:
- Vaginal, anal, or oral sex
- Genital skin-to-skin contact
- Sharing sex toys without cleaning or covering
- Kissing (less common, but possible if a sore is present)
Can you get syphilis from a toilet seat or casual contact?
No. Syphilis isn’t spread by toilet seats, towels, utensils, hugging, or sharing food.
Is syphilis contagious without symptoms?
Yes — especially in the early stages, when sores may be hidden or go unnoticed. Even without symptoms, you can still pass the infection to others.
Can you get syphilis more than once?
Yes. Treatment clears the current infection, but it doesn’t make you immune. You can get reinfected if you’re exposed again.
How Do You Test for Syphilis?
Syphilis is diagnosed through blood tests and, if there’s a sore, a direct swab.
Common syphilis tests:
- Blood tests: Detect antibodies your body makes in response to the infection (can remain positive for life)
- Swab test: If a sore is present, fluid may be tested for the bacteria
- CSF test: If neurologic symptoms exist, spinal fluid may be tested
When to get tested:
- If you have symptoms or a partner who tested positive
- During pregnancy (part of routine prenatal screening)
- If you’re a man who has sex with men
- After unprotected sex with a new or multiple partners
Is syphilis included in standard STI panels?
Sometimes — but not always. Be sure to ask specifically for a syphilis test if you’re unsure.
How Is Syphilis Treated?
Syphilis is cured with antibiotics, usually a single injection of benzathine penicillin G. The earlier you treat it, the easier it is to cure — and the less risk there is of complications.
Standard treatments:
- Early syphilis: One shot of penicillin
- Late latent or unknown-duration: Three shots over three weeks
- Neurosyphilis or ocular syphilis: IV penicillin for 10–14 days
If you’re allergic to penicillin, other antibiotics may be used — but you might be referred to an allergy specialist to safely receive penicillin.
How long after treatment is syphilis gone?
You’re no longer contagious after completing treatment, but the infection doesn’t vanish instantly from your records. Blood tests for syphilis look for antibodies — not the bacteria itself — and those antibodies can stay in your system for life.
That means even after successful treatment, your syphilis test may still come back positive. What changes is the type of test result and the antibody levels. Your healthcare provider will compare results over time to confirm the infection has cleared and that your treatment worked.
So yes, you might test positive even after being cured — and that’s normal. Follow-up care is how your provider tracks your recovery.
Complications of Syphilis
Untreated syphilis can lead to serious long-term health problems:
- Neurological damage (neurosyphilis): headaches, coordination issues, personality changes
- Heart and blood vessel damage (cardiovascular syphilis)
- Vision loss (ocular syphilis)
- Stillbirth or birth defects if passed during pregnancy (congenital syphilis)
Early treatment prevents all of these. But once damage is done, it may not be reversible.
Outlook & Prognosis
Syphilis is highly curable with antibiotics — especially in the early stages. Most people make a full recovery with no long-term effects.
But it’s also persistent. You can get syphilis again. You can pass it without symptoms. And you can develop serious complications if you ignore it.
That’s why regular testing and honest communication are key.
Living With Syphilis
If you’ve just been diagnosed with syphilis, it’s normal to feel overwhelmed — or ashamed. But here’s the truth: syphilis is common, curable, and nothing to be ashamed of.
Take your medication. Get your partner(s) tested and treated. Go to your follow-up appointments. Once treated, you’re cleared — but regular testing is a good idea.
There’s no long-term stigma when you prioritize your health. You did the responsible thing by finding out.
How to Tell Your Partner(s) You Have Syphilis
Telling a partner you have syphilis can feel awkward. But honesty protects you both — and helps stop the spread.
You can say:
“I found out I have syphilis. It’s a bacterial infection that’s easy to treat, but I wanted you to know so you can get tested too.”
Key things to highlight:
- It’s curable
- It’s often silent
- You’re telling them out of care and responsibility
This isn’t about blame. It’s about keeping each other safe and healthy.
Last reviewed: May 2025
This content is regularly reviewed and updated to reflect the latest medical guidelines.
- Caused by: Bacteria (Treponema pallidum)
- Spread through: Oral, vaginal, or anal sex; genital skin-to-skin contact; kissing if a sore is present
- Symptoms: Painless sore (chancre), rashes, swollen lymph nodes, fatigue — or no symptoms
- Testing: Blood test or swab of a sore; spinal tap if neurological symptoms
- Treatment: Curable with penicillin injections
- Risk if untreated: Brain damage, heart problems, blindness, congenital syphilis
- How common: Over 175,000 U.S. cases in 2021 (CDC)