Syphilis

A sexually transmitted bacterial infection that starts as a painless sore and can cause serious problems if untreated. It's curable with antibiotics.

InfectionSexual healthLast updated: 21 October 2026

Quick Summary

Primary Symptoms

A painless sore on the genitals or mouth, then a rash on palms and soles, fever and swollen glands; later stages can affect the heart and brain.

Common Treatments

Penicillin injections; partners should be tested and treated.

Risk Factors

Unprotected sex, multiple partners and mother-to-baby spread in pregnancy.

OverviewSymptomsCausesTreatmentFAQ

Overview

Syphilis is caused by Treponema pallidum. Symptoms come in stages and can disappear, even though the infection remains.

Pregnant women are tested because syphilis can seriously harm the baby.

Symptoms

Painless sore

At the site of infection.

Rash

Often on palms and soles.

Flu-like symptoms

Fever and swollen glands.

Late complications

Nerve, brain or heart damage.

Causes & Risk Factors

Biological Causes

Infection with Treponema pallidum through sexual contact or from mother to baby.

Key Risk Factors

  • Unprotected sex Not using condoms.
  • Multiple partners Or a partner with other partners.
  • Previous STIs Increase risk.

Management & Treatment

01. Antibiotics

Penicillin injection.

02. Partner treatment

Test and treat partners.

03. Follow-up

Blood tests to confirm cure.

Frequently Asked Questions

Can it be cured?
Yes, with antibiotics.
Can I get it again?
Yes, if exposed again.

Sources and further reading

Last updated 21 October 2026. For more detail, see these trusted health organisations.