The symptoms of syphilis are similar for men and women.
Some people with syphilis have no symptoms and even if they do, they're often mild and difficult to recognise, so you may pass on the infection without knowing you have it.
The symptoms also tend to change over time and may come and go.
Syphilis infection occurs in three stages, each with their own distinct symptoms :
The first symptoms of syphilis usually develop around two or three weeks after infection, although they can start later than this.
This stage of the infection is known as "primary syphilis".
Stage 1: Primary syphilis ( 2-3 weeks after infection)
Small, painless sores or ulcers (chancres) that typically appear on the penis, vagina, or around the anus, but can occur in other places such as the mouth. The infection is spread by contact with these sores.
Swollen glands in your neck, groin or armpits may also occur.
These symptoms usually pass within 3 to 8 weeks. But if the infection isn't treated, it may progress to a second stage
Stage 2: Secondary syphilis (occurs 4-10 weeks after initial chancre)
This next stage of syphilis can cause flu-like symptoms such as tiredness, headaches, joint pains, a high temperature (fever).
Wart like lesions on the genitals, patchy hair loss, white patches in the mouth and a non-itchy or itchy blotchy red rash that often affects the palms of the hands or soles of the feet.
These symptoms usually pass within a few weeks, although they may come and go over several months before they disappear.
There is a greater risk of passing the infection to other people during the primary and secondary stages.
After these initial stages, a hidden or latent stage occurs where no symptoms are experienced. This can last for years. However, if it's left untreated, syphilis can spread to the brain or other parts of the body and cause serious, long-term problems.
Stage 3: Tertiary syphilis ( 20-40 years after initial infection)
This third stage of syphilis is the most dangerous, affecting around a third of people who are not treated for syphilis in the earlier stages. Tertiary syphilis can cause damage to the brain, nerves, eyes, heart, bones, skin or blood vessels. This may lead to serious or even life-threatening conditions including stroke, heart disease, dementia, loss of co-ordination, numbness, paralysis or becoming blind or deaf.
Syphilis is still treatable at this stage, but it's sometimes not possible to reverse any damage that's already been done.
People with syphilis are around three to five times more likely to be infected with HIV, which can enter the body through any syphilis sores that start to bleed during sex.