Syphilis: Causes, Symptoms by Stage, and How It’s Treated

You notice a small, painless sore. It doesn’t itch. It doesn’t hurt. A few weeks later, it’s gone on its own — so you forget about it. Here’s the problem: with syphilis, that vanishing sore isn’t a sign you’re better. It’s a sign the infection has moved deeper.

Syphilis is one of the most misunderstood infections out there. It’s also one of the most curable — if it’s caught. Let’s talk about what it actually is, how it shows up at each stage, and what treatment really looks like.

Jump to a sectionIn this article8 sections

1. What Causes Syphilis?
2. Syphilis Symptoms by Stage
3. The Stage Myth Worth Correcting
4. Congenital Syphilis: The Part That Deserves Your Full Attention
5. How Syphilis Is Diagnosed and Treated
6. Fact vs. Fiction
7. Actionable Tips
8. The Bottom Line

What Causes Syphilis?

Syphilis is caused by a bacterium called Treponema pallidum. It’s not a virus. It’s not caused by poor hygiene, and it’s not something you can catch from a toilet seat, a doorknob, or a swimming pool.

It spreads through direct contact with a syphilis sore — called a chancre (pronounced SHANK-er). These sores can appear on the genitals, inside the vagina, around the anus, in the rectum, or on the lips and inside the mouth.

That contact usually happens during vaginal, anal, or oral sex. It can also pass from a pregnant person to their baby, which is called congenital syphilis.

Why It’s So Easy to Miss

Here’s what makes this sexually transmitted infection different from most others: the early sore is typically painless. It doesn’t demand your attention. It may sit somewhere you can’t easily see — inside the vagina, in the rectum, or in the mouth.

And it heals on its own within a few weeks, whether or not you get treated.

So a lot of people never seek care. The sore leaves. The bacteria stay.

Who’s at Risk?

Anyone who is sexually active can get syphilis. But risk goes up with:

• Having sex without a condom or other barrier
• Having multiple partners, or a partner with multiple partners
• Having another STI, including HIV
• Being pregnant without prenatal screening

One thing worth knowing: syphilis rates in the United States have risen sharply in recent years, including cases in newborns. This isn’t a “rare, old-fashioned” disease anymore. It’s very much a current one.

Syphilis Symptoms by Stage

Syphilis progresses in stages. Understanding the stages of syphilis is the key to understanding why it’s so often caught late.

Primary Stage

This is where it starts, usually about three weeks after exposure — though it can range from about 10 days to three months.

The hallmark sign is a chancre: a firm, round, painless sore at the spot where the bacteria entered the body. There may be one sore, or several.

⚠️ Because it’s painless and often hidden, many people never notice it at all. The chancre heals on its own in roughly three to six weeks — with or without treatment.

Healing is not the same as curing. If untreated, the infection moves on.

Secondary Stage

Weeks to months after the chancre fades, new syphilis symptoms can appear. This stage is sometimes called “the great imitator” because it mimics so many other conditions.

Common signs include:

• A rash, often rough and reddish-brown, that classically shows up on the palms of the hands and soles of the feet — an unusual spot for most rashes
• Flat, moist, wart-like sores in warm areas like the groin or underarms
• Fever, sore throat, headache, muscle aches
• Swollen lymph nodes
• Patchy hair loss
• Fatigue

The rash usually doesn’t itch. That’s part of why it gets dismissed.

Here’s the frustrating part: these symptoms also go away on their own. Which is exactly why so many people conclude they had “a bug” and move on.

Latent Stage

Now the infection goes quiet. No sores. No rash. No symptoms at all.

But the bacteria are still in the body, and blood tests will still come back positive. This stage can last for years.

Early in the latent stage, a person can still transmit syphilis to a sexual partner. Later on, sexual transmission becomes less likely — but transmission during pregnancy remains possible.

Tertiary Stage

Most people with untreated syphilis never reach this stage. But some do, sometimes 10 to 30 years after the original infection.

Tertiary syphilis can cause severe damage to the heart, blood vessels, brain, nerves, liver, bones, and joints. It can be disabling. It can be fatal.

By this point, antibiotics can stop the bacteria — but they cannot repair organs that are already damaged.

The Stage Myth Worth Correcting

A lot of older health articles say that syphilis only affects the brain, eyes, and ears in the late stage. That’s outdated.

Current guidance is clear: neurosyphilis (infection affecting the brain and nervous system), ocular syphilis (affecting the eyes), and otosyphilis (affecting the ears) can occur at any stage of the infection, including early on.

Signs that warrant urgent medical attention include:

• Severe headache, neck stiffness, or confusion
• Changes in vision, eye pain, or vision loss
• Sudden hearing loss, ringing in the ears, or dizziness
• Muscle weakness or trouble with coordination

Would you assume a headache and blurry vision could be an STI? Most people wouldn’t. That’s precisely why this matters.

Congenital Syphilis: The Part That Deserves Your Full Attention

If a pregnant person has untreated syphilis, the infection can pass to the baby. This is called congenital syphilis, and it is serious.

It can lead to miscarriage, stillbirth, premature birth, low birth weight, or death shortly after birth. Babies who survive may have bone damage, anemia, enlarged liver and spleen, jaundice, nerve problems, blindness, or deafness. Some show no symptoms at birth and develop problems later.

Here’s the part that should give everyone hope: this is largely preventable.

Syphilis testing is a standard part of prenatal care. When the infection is found and treated early enough in pregnancy, the baby is very likely to be protected. Many health authorities now recommend testing more than once during pregnancy in areas where rates are high.

💡 If you are pregnant or planning to become pregnant, ask directly: “Was I tested for syphilis, and what was the result?” Don’t assume. Ask.

Important: penicillin is the only recommended treatment during pregnancy. People with a penicillin allergy need to be desensitized under medical supervision so they can receive it safely. No other antibiotic is considered a reliable substitute for protecting the baby.

How Syphilis Is Diagnosed and Treated

Testing

Diagnosis is usually made with a blood test. In some cases, a provider may take fluid from a sore, or perform a spinal fluid test if neurosyphilis is suspected.

Testing is simple, quick, and widely available — at doctor’s offices, sexual health clinics, and many community health centers.

Treatment

Syphilis treatment is antibiotics — specifically, penicillin, given by injection. It is highly effective, and it has been for decades. The bacteria have not developed meaningful resistance to it.

The number of doses depends on how long the person has had the infection, which is why staging matters. People with certain penicillin allergies may have alternatives in some non-pregnancy situations, but those decisions belong to a clinician.

Three things people are often surprised to learn:

1. Treatment cures the infection. It does not reverse damage already done. Vision loss, heart damage, and nerve damage may be permanent.
2. You do not become immune. You can get syphilis again after being cured.
3. Partners need testing and treatment too, or reinfection is likely.

Follow-up blood tests are used to confirm the treatment worked. Don’t skip them.

Fact vs. Fiction

❌ What People Believe	✅ What’s Actually True
“The sore went away, so I’m fine.”	Sores heal on their own. The infection continues.
“Syphilis is basically extinct.”	Rates have risen sharply, including in newborns.
“Only the late stage affects the brain or eyes.”	Brain, eye, and ear involvement can happen at any stage.
“I’d know if I had it.”	Early symptoms are painless, hidden, and easy to miss.
“Condoms make it impossible to catch.”	They lower risk substantially, but sores outside the covered area can still transmit it.
“Once treated, I can’t get it again.”	Reinfection is entirely possible.
“A rash on my palms is just dry skin.”	A palm-and-sole rash is a classic secondary syphilis sign.

Actionable Tips

Get tested — and be specific. A “full STI panel” doesn’t always include syphilis. Ask for it by name.

Test during pregnancy, early. And ask whether repeat testing is recommended where you live.

Use barriers consistently. Condoms and dental dams meaningfully reduce risk, even if they don’t eliminate it.

Talk to partners before, not after. Awkward for five minutes. Protective for years.

Don’t self-diagnose a rash. Especially one on your palms or soles that doesn’t itch.

Finish follow-up testing. Treatment isn’t confirmed complete until blood work says so.

Take any new vision, hearing, or neurological symptom seriously if you’ve had a possible exposure — at any stage.

Skip the internet self-treatment. There is no home remedy, supplement, or protocol that cures a bacterial infection like this one. Antibiotics from a clinician, full stop.

The Bottom Line

Syphilis carries a lot of shame — and that shame is exactly what keeps it spreading. The infection doesn’t care about your character, your relationship status, or how careful you thought you were being. It cares about whether it gets found.

And here’s the genuinely good news: syphilis is curable. The treatment is old, cheap, effective, and available. The test is a blood draw. The hardest part of the entire process is usually just deciding to ask for it.

You are allowed to protect your health without apologizing for it. If any of this sounds familiar — a strange sore, an odd rash, a partner who tested positive, a pregnancy without a confirmed screening — make the appointment. Not next month. This week.

Catching syphilis early costs you one conversation and one needle. Catching it late can cost you a great deal more. That math is worth respecting.

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your personal health, especially if you are pregnant or think you may have been exposed to a sexually transmitted infection.

Keep going: this article is part of my natural healing and healthy living guide. For every guide, free tool, and honest review, organized by where you are stuck, visit the Hormone Health Hub.