Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
About Syphilis
Syphilis is a sexually transmitted infection (STI) caused by bacteria. It infects the genital area, lips, mouth, or anus of both men and women. You usually get syphilis from sexual contact with someone who has it. It can also pass from mother to baby during pregnancy.
The early stage of syphilis usually causes a single, small, painless sore. Sometimes it causes swelling in nearby lymph nodes. If you do not treat it, syphilis usually causes a non-itchy skin rash, often on your hands and feet. Many people do not notice symptoms for years. Symptoms can go away and come back.
The sores caused by syphilis make it easier to get or give someone HIV during sex. If you are pregnant, syphilis can cause complications, or you could lose your baby. In rare cases, syphilis causes serious health problems and even death.
Syphilis is easy to cure with antibiotics if you catch it early. Correct usage of latex condoms greatly reduces, but does not completely eliminate, the risk of catching or spreading syphilis. If your or your partner is allergic to latex, you can use polyurethane condoms. The most reliable way to avoid infection is to not have anal, vaginal, or oral sex.
Centers for Disease Control and Prevention
It sits within Infections, Sexual Health Issues, Female Reproductive System and Male Reproductive System.
The lead U.S. institute for this subject is the National Institute of Allergy and Infectious Diseases.
When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.
Research on Syphilis
154 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.
What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.
Research currently under way
- A Randomized Controlled Trial of Doxycycline Post Exposure Prophylaxis to Prevent Incident Bacterial STIs Among Women in the United StatesTulane University
- Feasibility and Acceptability of Point of Care Rapid Syphilis Testing Among Patients Seeking Family Planning Services in Hawai'iQueen's Medical Center
- The Feasibility of Implementing Syphilis Point-of-care Testing Into a Prenatal Clinic for People Facing Barriers to CareMcMaster University
- Superiority of On-demand PrEP Versus PEP on Using Doxycycline for Preventing STI in MSMChinese University of Hong Kong
- Evaluation of Antimicrobial Prophylaxis to Prevent Syphilis in Pregnancy in Patients at Risk in Rio de Janeiro, BrazilUniversity of California, Los Angeles
- Doxycycline Prophylaxis for Prevention of Sexually Transmitted InfectionsWestat
Research already completed
- Alternative Antibiotics for SyphilisFundación FLS de Lucha Contra el Sida, las Enfermedades Infecciosas y la Promoción de la Salud y la Ciencia
- Ending the HIV Epidemic Through Point-of-Care Technologies (EHPOC)Johns Hopkins University
Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.
Where to read more
Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.
Start Here
- About SyphilisCenters for Disease Control and Prevention
- SyphilisMayo Foundation for Medical Education and Research
Diagnosis and Tests
- Syphilis TestsNational Library of Medicine
Related Issues
- Chlamydia, Gonorrhea, and SyphilisAmerican College of Obstetricians and Gynecologists
- NeurosyphilisNational Institute of Neurological Disorders and Stroke
Statistics and Research
- SyphilisNational Institute of Allergy and Infectious Diseases
Clinical Trials
- ClinicalTrials.gov: SyphilisNational Institutes of Health
Medical subject headings
Clinicians and researchers index this subject under Syphilis. These are the terms to use when searching medical literature.
This page is built from the MedlinePlus health topic record for Syphilis, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.