Medically Reviewed by Zilpah Sheikh, MD on February 18, 2024
9 min read

Syphilis is a highly contagious disease that’s mostly spread through sexual activity, including vaginal, oral, and anal sex. It can stay in your body for a long time before it causes symptoms. You might not know that you have it and then pass it on to your sexual partner.

Early syphilis causes sores, rashes, and other symptoms. If left untreated, it can cause serious long-term problems that affect the brain, eyes, heart, and other organs. Early syphilis can be treated with the antibiotic penicillin. It's harder to treat as it gets worse. That's why it's important to see your doctor if you notice any symptoms or think you may have been exposed to the bacteria.

Syphilis is caused by the bacteria Treponema pallidum. You get it through direct contact with a syphilis sore on someone else’s body. The bacteria can also get into your body through cuts on your skin or through your mucous membranes. This usually happens during sexual activity. You can also get it through other forms of direct contact, such as sharing needles with someone who is infected while taking intravenous (injected) drugs.

Babies can have congenital (from birth) syphilis if their mother has it during pregnancy. It's also possible for babies to get it by breastfeeding. 

Syphilis can’t be spread by toilet seats, doorknobs, swimming pools, hot tubs, bathtubs, shared clothing, or eating utensils.

Any sexually active person can get syphilis. But you’re at higher risk of getting syphilis if you:

  • Have unprotected sex
  • Have more than one sex partner
  • Have HIV, which is the virus that causes AIDS
  • Are positive for another STD such as gonorrhea, chlamydia, or herpes

People assigned male at birth are more likely to have syphilis than people assigned female at birth. People assigned male at birth are also at higher risk if they have sex with other people assigned male at birth.

The first symptom of syphilis is a small sore called a chancre (SHANG-kur). The sore is usually firm, round, and painless. It is located where the syphilis bacteria enters your body, such as your penis, vagina, anus, rectum, lips, or mouth. Because it doesn’t hurt, some people never notice the chancre. It may be mistaken for a pimple or hidden from view inside the vagina or rectum.

After a while, you may have these symptoms:

  • Rash
  • Sores
  • Fever
  • Swollen lymph nodes
  • Sore throat
  • Headaches
  • Patchy hair loss
  • Weight loss
  • Muscle aches
  • Fatigue (tiredness)

Syphilis rash

The rash can appear on one or more parts of your body, including the palms of your hands and soles (bottoms) of your feet. Usually, it shows up first on the trunk of your body (your chest, stomach, pelvis, or back). Your rash may show up while you still have a sore or weeks later. The rash usually doesn’t itch. It may be red or reddish-brown in color and feel rough to the touch. Sometimes it is so light you may not notice it.

Syphilis sore

After the early chancre, you might get some wart-like sores. These can appear in your mouth or near your genital area (penis, vagina, or anus).

There are four stages of syphilis:

Early or primary syphilis 

This is when chancres show up. They heal without a scar within 3-6 weeks without medical treatment. But the disease is still there, so it's important to get treatment before you go into the second stage.

Secondary syphilis 

This stage begins with a rash on your chest, stomach, pelvis, or back. Later, it might appear on your hands and feet. These may look like rashes caused by other diseases. Syphilis rash usually doesn't itch like other rashes. It can range in appearance from red to reddish-brown, or it may be so light that it's barely noticeable. As with primary syphilis, symptoms of secondary syphilis will get better without treatment. But the disease has not gone away.

Latent syphilis

If you don’t get treatment for syphilis, the disease will move from the secondary stage to the latent or “hidden” stage. During this stage, you will have no symptoms. The latent stage can last for years and fool you into believing you no longer have syphilis bacteria in your body. For some people, symptoms never return; but for others, if untreated, the disease will move to the final stage. The health risks at that stage are very serious, which is why it’s so important to treat syphilis, even if symptoms go away on their own.

Tertiary or late syphilis

In this advanced stage, syphilis can cause problems with your heart, brain, blood vessels, liver, bones, joints, and nerves. Up to 30%-40% of people who don’t get treatment for syphilis reach the tertiary stage. You could become paralyzed (unable to move), blind, or deaf, or get dementia or impotence. It can even be deadly.

Without treatment, syphilis can spread to your brain and nervous system during any of the four stages. This condition is called neurosyphilis. Neurosyphilis can cause severe headaches, muscle weakness or paralysis, confusion or trouble focusing, or dementia.

Syphilis can also spread to the eye (ocular syphilis) and cause eye pain, redness, vision problems, or blindness. 

When syphilis spreads to your ear (otosyphilis), it can cause hearing loss, tinnitus (ringing or buzzing in your ear), dizziness, or vertigo (feeling like the room is spinning).

If you don’t get treatment, syphilis can cause complications all over your body:

Small bumps. Bumps called gummas can grow on your skin, bones, or organs. They can destroy the tissue around them.

Nervous system problems. Syphilis can cause problems such as headaches, stroke, brain damage, paralysis, bladder issues, or difficulty getting an erection.

Cardiovascular problems. The disease can damage your heart valves or cause bulging blood vessels (aneurysms) or an inflamed aorta, which is the blood vessel that carries oxygen and nutrients throughout your body.

HIV. Syphilis can increase your chance of getting HIV.

Pregnancy and childbirth problems. If you’re pregnant, you could pass syphilis to your unborn baby. This condition, congenital syphilis, can lead to miscarriage, stillbirth (birth of an infant who has died before delivery), or death of your newborn.

Your unborn baby can become infected with syphilis through the placenta, the organ that provides nutrients and oxygen in the womb. Infants can also become infected during birth.

The CDC says pregnant people should be tested for syphilis at least once during pregnancy. It’s best if you're tested at your first prenatal visit. Depending on how long you've had syphilis, you have a high chance of stillbirth, or giving birth to an infant who has died before delivery. There's also a high chance your newborn could die shortly after birth. 

If you pass it to your baby, it may be born without symptoms but could have them within a few weeks if the disease isn’t treated right away. These signs and symptoms can be very serious. Untreated babies may experience delayed development, seizures, or even death.

Babies born with syphilis may have:

  • Sores and rashes
  • Fever
  • Jaundice (yellowing of skin and eyes)
  • Anemia (not enough red blood cells)
  • Swollen spleen and liver
  • Sneezing or stuffed, drippy nose
  • Bone changes

Later signs may include:

  • Deafness
  • Teeth problems
  • Collapse of the bridge of the nose (saddle nose)

Your doctor will need to do a physical exam. They might give you tests including:

  • Blood tests. A quick test at your doctor’s office or a public health clinic can diagnose syphilis. This is the main way syphilis is diagnosed.
  • Cerebrospinal fluid tests. If your doctor thinks you might have neurosyphilis, they’ll test fluid taken from around your spinal cord.
  • Darkfield microscopy. Syphilis bacteria are visible through a microscope in fluid taken from a skin sore or lymph node.

Syphilis is curable with quick diagnosis and treatment. But if it’s treated too late, it can permanently damage your heart and brain even after the infection is gone.

Because syphilis is caused by a bacterial infection, it is treated with an antibiotic. Penicillin is the most commonly used antibiotic (medication) for syphilis. It’s important to finish taking all of the medication your doctor prescribes, even if your symptoms go away.

Don’t have sexual contact until the infection is completely gone. Let your current sexual partners (as well as any from the last 2 years) know they should also be tested and, if necessary, treated. If your partner is infected and not treated, they could reinfect you.

Some people with syphilis have an immune system reaction called a Jarisch-Herxheimer reaction several hours after their first treatment. This might include fever, chills, headache, upset stomach, rash, or joint and muscle pain. These problems usually go away within 24 hours.

After you have finished your treatment, your doctor may want to do additional tests, such as blood work, to make sure the infection is gone.

Syphilis medication

If you've had syphilis for less than a year, one dose of penicillin is usually enough to kill the infection. This is given by injection into your muscle. If you’re allergic to penicillin, you might get another antibiotic instead, such as doxycycline or ceftriaxone. If you’re in a later stage of the disease, you’ll need more doses.

You should not take doxycycline if you’re pregnant. Your doctor will decide what medication is best for you based on your case.

Is syphilis curable?

Syphilis is 100% curable if treated with the correct antibiotics. However, antibiotics cannot repair long-term damage to your organs caused by the infection. This is why it’s important to seek treatment before syphilis reaches the latent or tertiary stage.

Can I live a normal life after syphilis?

If you receive treatment with antibiotics during the primary or secondary stage of syphilis, you can recover from the infection and avoid long-term health problems. Without treatment, syphilis can cause serious health problems and death. If you’ve had syphilis, you can get it again. Be sure to practice safe sex and get tested often if you are at high risk for sexually transmitted infections.

You can get syphilis again after treatment kills the infection. The only way to avoid syphilis altogether is to not have anal, oral, or vaginal sex. But you can reduce your risk of syphilis infection:

  • Don’t have intimate contact with someone if you know they’re infected.
  • If you don’t know whether a sexual partner is infected, use a condom every time you have sex. Make sure you use the condom correctly. Syphilis can still spread if lesions aren't properly covered by a condom.
  • Use a dental dam when you have oral sex. These are thin sheets of polyurethane used to provide a barrier between the mouth and vagina or anus.
  • Don't share sex toys.
  • Be in a long-term, mutually monogamous relationship with someone who doesn't have syphilis.

If you are in a relationship with someone who has syphilis, you're at risk as well. You may need to get treatment based on your specific case. Talk to your doctor to figure out the best way to treat or prevent a syphilis infection.

If you are diagnosed with syphilis, you need to let your sex partner(s) know so that they can be tested and treated. This includes your current partners and any you have had over the last 2 years. If your current partner has syphilis, they can reinfect you after you’ve been treated. It’s important that you both get treated so you don’t keep passing syphilis to each other.

After you find out you have syphilis, you may be contacted by your local health department. An employee from the department will talk to you about private ways to let your partners know they have been exposed to syphilis. You can ask the health department to do this for you without sharing your identity with your partners. They can also help you tell your partners through a free service called “partner notification.” Your health department can also assist you in finding treatment and counseling services.

Don’t engage in any sexual activity until you’ve completed treatment with antibiotics and tests show that you are no longer infected. Wait until your partner has finished treatment to prevent reinfection.

Syphilis is a highly contagious disease that is caused most often through sexual contact. It is 100% curable if treated correctly with antibiotics. If your infection is left untreated, even if your symptoms go away, it can cause very serious, long-term health problems and even death. Talk to your doctor right away if you think you have or have been exposed to syphilis.