Syphilis: symptoms, stages, treatment and how to tell your partner
Syphilis is a sexually transmitted infection caused by a bacterium. At first it can go unnoticed, because the first sore is painless and heals on its own, but it is cured with penicillin if treated in time. Here you will find its symptoms, how it is treated and how to tell your partner.
What is syphilis?
It is an infection caused by the bacterium Treponema pallidum. It progresses in stages and, without treatment, can stay in the body for years and damage the heart, brain, eyes and other organs. It also makes it easier to get HIV.
Syphilis symptoms and stages
- Primary syphilis: between 10 and 90 days after infection (about 3 weeks on average), a painless sore or ulcer (chancre) appears on the genitals, anus or mouth. It heals on its own within a few weeks, but the infection remains.
- Secondary syphilis: weeks later a skin rash may appear, often on the palms of the hands and the soles of the feet, along with fever, feeling unwell, swollen glands or hair loss.
- Latent syphilis: there are no symptoms, but the infection continues and shows up in blood tests. It can last for years.
- Tertiary syphilis: years later, in some untreated people, it can damage the heart, the nervous system and other organs.
At any stage it can affect the eyes, hearing or nervous system. If you notice changes in your vision or hearing, seek medical care right away.
How is syphilis spread?
It spreads through direct contact with the sore or lesions during vaginal, anal or oral sex. Condoms lower the risk, but do not eliminate it if the sore is in an area the condom does not cover. It can also pass from mother to baby during pregnancy. It is not spread by sharing clothes, cutlery or toilets.
Testing and diagnosis
It is diagnosed with a blood test and, if there is a sore, a sample taken from it. You can get tested by your doctor, at a sexual health clinic or at some community organizations. If you test positive, also get tested for HIV and other STIs.
Syphilis treatment
Syphilis is cured with penicillin, usually given as an injection into a muscle. In the early stages a single dose is usually enough; later stages need more doses. If you are allergic to penicillin, your doctor will prescribe an alternative. Treatment clears the infection, but it does not repair damage that has already been done.
In the hours after the injection you may have fever, chills or muscle aches: this is a known reaction that passes quickly. Do not have sex until your doctor says so, the sores have healed and your partners have been treated. Blood tests are repeated afterwards to confirm the cure.
How to tell your partner you have syphilis
Telling your partner allows them to get treated before the infection progresses and stops them from passing it back to you. Some tips:
- Do it as soon as possible: if the contact was in the last 3 months, they are usually treated even if their blood test is negative.
- Choose the moment and the way: in person if it is your steady partner; with a casual partner, a call or a message may be enough.
- Stick to the facts, without blame: syphilis can go unnoticed for a long time, so the diagnosis does not tell when or from whom it came.
- Let them know it can be cured: penicillin cures it, and the sooner it is treated, the better.
If you cannot or do not want to tell them yourself, you have two options: ask for help at your healthcare center, where in some cases the staff notify contacts for you, or send an anonymous text message or email with STI notice, without your name or number appearing.
Who should you notify?
It depends on the stage at which you were diagnosed. As a guide, clinical guidelines recommend:
- Primary syphilis: partners from the last 3 months, plus the time you have had symptoms.
- Secondary syphilis: partners from the last 6 months, plus the time you have had symptoms.
- Early latent syphilis: partners from the last year.
Your doctor will tell you the period that applies in your case.
If you have been told you might have syphilis
Make an appointment with your doctor or a sexual health clinic and explain that a partner has tested positive. You will have a blood test and, if the contact was in the last 3 months, you will usually be treated even if the result is negative, because the test can take weeks to detect the infection. In the meantime, avoid sex and check yourself for any sores or rash.
How to prevent syphilis
Use condoms for vaginal, anal and oral sex, and get tested regularly if you have new or multiple partners. If you see a sore or a rash on your partner, do not have sex until it has been checked.
Frequently asked questions about syphilis
Can you get syphilis from oral sex or kissing?
From oral sex, yes: it is a common route. From kissing it is possible but uncommon, and only if there is a sore or lesions in the mouth.
Why do I still test positive after treatment?
Because one of the tests (the treponemal test) detects antibodies that usually stay for life. To check whether you are cured, another test (RPR or VDRL) is used, and its value should drop in the months after treatment.
Can I get syphilis again?
Yes. Having had syphilis does not protect you from a new infection, which is why it is important that your partners are treated and that you use condoms.
What happens if I am pregnant and have syphilis?
Syphilis can pass to the baby and cause miscarriage, premature birth or congenital syphilis. That is why it is tested for during pregnancy care. Penicillin treatment is safe and effective during pregnancy.
Other sexually transmitted infections
Gonorrhea · Genital herpes · HIV · Pubic lice (crabs) · HPV and genital warts · Chlamydia · Yeast infection (candidiasis) · Hepatitis A, B and C · Trichomoniasis · Scabies · Mpox (monkeypox)
Sources: MedlinePlus: primary syphilis; CDC: syphilis treatment guidelines.Health information updated in October 2026. It does not replace advice from a healthcare professional.