Syphilis (SIH-fih-lis) is a sexually transmitted disease that can lead to serious lifelong physical problems, including blindness and paralysis * , if left untreated.

What Is Syphilis?

Syphilis is a disease that is caused by the bacterium Treponema pallidum (treh-puh-NEE-muh PAL-ih-dum). The disease develops in three distinct phases. The first, or primary, stage is marked by a chancre * . In the secondary stage, a rash develops. There can be an interval of months to years for late syphilis to develop, if early stages are not detected and treated. By the third stage, also known as the tertiary stage, the disease can cause widespread damage to the body, affecting the brain, nerves, bones, joints, eyes, heart, and other organs. Syphilis does not advance to this point in all infected people, and it does so only if it has not been treated adequately during either of the two earlier stages.

Without treatment, syphilis can be fatal. It can also have serious consequences for the fetus * of an infected woman. If a pregnant woman has syphilis, she can pass it to her unborn offspring, a condition known as congenital * syphilis. Because the immune system * of a baby is not developed fully until the infant is well into the first year of life, infection with syphilis bacteria * can lead to severe complications. Among pregnant women who are infected but are not treated, up to 80 percent of their fetuses may become infected, and up to 40 percent may die before or shortly after birth.


Over the centuries, the disease syphilis has been called by many names. The term great pox was used to differentiate syphilis from smallpox. The name syphilis seems to have originated in a 1530 poem about a shepherd named Syphilis, which was written by the Italian physician Girolamo Fracastoro (Fracastorius) (1478–1553). The poem was titled “Syphilis, sive morbus Gallicus” (meaning “Syphilis, the French disease”).

In his play Timon of Athens, William Shakespeare (1564–1616) refers to syphilis as the “infinite malady.”

Cultural embarrassment caused many nations to refer to syphilis as the disease of another national group. The English and Germans called it the French pox. The Russians claimed to suffer from the Polish sickness. The Poles identified syphilis as the German sickness. The French named it the Neapolitan sickness (meaning Italian or from the area around Naples, Italy). The Flemish, Dutch, Portuguese, and North Africans caught the Spanish or Castilian sickness. Meanwhile, the Japanese referred to syphilis as the Canton rash or the Chinese ulcer.

How Common Is Syphilis?

Syphilis was rampant in the United States until the antibiotic penicillin was introduced in the 1940s. After that, the number of syphilis cases dropped. The reduction in the rate of primary and secondary syphilis in the United States was particularly noticeable between 1990 and 2000, when it fell nearly 90 percent. By 2000 the rate was at its lowest level since reporting began in 1941, according to the Centers for Disease Control and Prevention (CDC). After that, syphilis cases rose again. In 2013, there were 56,471 reported new cases of syphilis; 17,535 of those were of primary and secondary (P&S) syphilis.

One demographic shift reflects increased reporting of cases among young men who have sex with men (MSM). In 2002, rates of primary and secondary syphilis were highest among men between 30 and 39 years old, but in 2013 rates were highest among men between 20 and 29 years old.

The CDC launched a “National Plan to Eliminate Syphilis,” which worked on many fronts to reduce the numbers. Some of these included enhancing public health services and assisting in syphilis-prevention efforts directed at targeted cultural groups.

Is Syphilis Contagious?

Syphilis is a sexually transmitted infection (STI) that spreads from person to person through vaginal * , oral * , or anal * sexual intercourse. A pregnant female can also pass the disease to her fetus. Syphilis is contagious during its first and second stages, and sometimes in the early latent period, which is described below. People are most contagious, however, during the second stage of the infection.

What Are the Signs and Symptoms of Syphilis?

Syphilis has been called the great imitator, because its symptoms can resemble those of many other diseases. Not all people have obvious symptoms, but in those who do, signs of disease appear 10 to 90 days after being infected. The first symptom is a small, usually painless sore known as a chancre that appears where the syphilis bacterium entered the body, often on the penis or the lips of the vagina * . Without treatment, chancres heal by themselves within six weeks. A person who is infected may never even notice a chancre, especially if it is inside the vagina or the rectum * .

One to two months after the chancre fades, the disease moves to its second stage. In this phase, a rash of rough, reddish or brownish spots appears on the body, including the soles of the feet and the palms of the hands. The rash may be so faint that it is barely noticeable. Second-stage symptoms of syphilis may also include fever, headache, extreme tiredness, sore throat, muscle aches, swollen lymph nodes * , weight loss, hair loss, and ulcers * on mucous membranes * in the mouth and on the genitals * . Wart-like lesions * may appear on the vagina or anus. These symptoms also disappear on their own, fooling many people into thinking that they have had an ordinary viral illness.

After the second-stage symptoms clear up, the disease enters a latent, or hidden, period in which the patient shows no signs of illness. The latent period can last for many years, and in some infected people the bacteria do no further damage. In about one-third of people who reach the latent period, the disease progresses to its final stage. This phase has no symptoms at first, but as the bacteria invade and damage nerves, bones, and the heart and other organs, the patient may experience dizziness, headaches, seizures * , dementia * , loss of coordination, numbness, increasing blindness, and paralysis * . The disease also can eat away at tissue in the mouth and nose, disfiguring the face. This last stage of the disease can begin two to 40 years after a person is first infected.

Babies who are born with syphilis may have symptoms at birth or may show signs of the disease within a few weeks or months. These symptoms include so-called failure to thrive * , or a failure to gain weight and grow at the expected rate; irritability; fever; rash; a nose without a bridge (known as saddle nose); bloody fluid from the nose; and a rash on the palms, soles, or face. As these children grow older, they may become blind and deaf, and may have notched teeth (called Hutchinson teeth). Bone lesions may arise, and lesions and scarring may appear around the mouth, genitals, and anus.

How Do Doctors Diagnose Syphilis?

* to the bacterium. If neuro-syphilis (NUR-o-SIH-fih-lis), which is syphilis that has progressed to the point that it affects the brain, spinal cord, and nerves, is suspected, the doctor may also order tests of the spinal fluid to look for antibodies. Routine prenatal care for pregnant women includes a screening for syphilis.

How Do Doctors Treat Syphilis?

Even though visible signs of the infection clear up on their own, doctors provide treatment for syphilis. Doing so prevents the disease from progressing to the late, potentially much more harmful stage; and in pregnant women, treatment prevents infants from suffering damage caused by the infection. Doctors can easily treat early-stage syphilis with antibiotics. They advise people who are infected with syphilis to notify all their recent sexual partners so that these people can be tested for the disease. Doctors are also required to report cases of syphilis directly to the Centers for Disease Control and Prevention (CDC). Patients with advanced cases of the disease often need hospitalization. They also receive antibiotics, although medications cannot reverse damage already done to the body.

Syphilis patient with symptoms indicative of the onset of the secondary stage of this disease. Symptoms include swollen or enlarged lymph nodes and accompanying lingual (tongue) mucous patches.

Syphilis patient with symptoms indicative of the onset of the secondary stage of this disease. Symptoms include swollen or enlarged lymph nodes and accompanying lingual (tongue) mucous patches.
CDC/Susan Lindsley.

How Long Does Infection Last?

A single dose of antibiotics can clear up syphilis infections that are less than a year old. Longer-term cases require longer courses of treatment. Congenital syphilis also needs a longer course of treatment. Without treatment, the disease can last for years or even decades.

Does Syphilis Have Complications?

Untreated cases of syphilis can lead to destructive tissue lesions known as gummas (GOOM-ahz) on the skin, bones, and organs; seizures; damage to the spine that can result in paralysis; heart problems; damage to blood vessels that can lead to stroke * ; and death. According to the CDC, a person with syphilis has a twofold to fivefold greater risk of acquiring human immunodeficiency (ih-myoo-no-dih-FIHshen-see) virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS), an infection that weakens the immune system. The reason for this increased risk is that open sores make an easy entry for HIV during sexual contact. Also, people infected with HIV are more likely to experience the neurological * complications of syphilis. In infants, syphilis can lead to hearing loss, blindness, neurological problems, and death.

Can Syphilis Be Prevented?


During the middle decades of the 20th century, syphilis was the subject of what became known as the most infamous public health study ever carried out in the United States. From 1932 to 1972, the U.S. Public Health Service conducted a study in Macon County, Alabama, to learn more about the long-term consequences of the disease. Six hundred poor African American men, 399 of them infected with syphilis, participated in the study in exchange for free medical exams, free meals, and burial insurance.

The Tuskegee Syphilis Study became notorious because local doctors who participated in the study were instructed not to treat the men's infections, even after an easy cure with penicillin became widely available in 1947. Although the men had agreed to be part of the project, they were never told they would not be treated fully for their condition. They were simply told that they were part of a study of “bad blood,” a local term used for several illnesses.

Public outrage erupted in 1972 when it became known that men with syphilis in the study had been allowed to remain untreated so that doctors could investigate the progression of the disease, and the project was stopped. That came too late for the men, however, and many had already been disabled permanently or had died. In the wake of the study, the government moved quickly to adopt policies that protect people who take part in research programs. In 1974 a new law created a national commission to set basic ethical standards for research. New rules also required that participants in government-funded studies be made fully aware of how a study will proceed and voluntarily agree to take part in it. In addition a review process ensures that any study involving human subjects meets ethical standards before it begins.

Of course, these changes could not reverse the physical and emotional harm done to the men in the Tuskegee Syphilis Study and to their families. In recognition of that harm, President Bill Clinton in 1997 offered an apology to the survivors, families, and descendants of those men on behalf of the U.S. government.

See also AIDS and HIV Infection • Bacterial Infections • Dementia • Gonorrhea • Pregnancy • Sexually Transmitted Infections (STIs): Overview


Books and Articles

Losse, Deborah N. Syphilis: Medicine, Metaphor, and Religious Conflict in Early Modern France. Columbus, OH: Ohio State University Press, 2015.

Reverby, Susan M. Examining Tuskegee: The Infamous Syphilis Study and Its Legacy. Chapel Hill, NC: University of North Carolina Press, 2013.

Waseem, Muhammed. “Pediatric Syphilis.” Medscape, April 1, 2013. (accessed July 13, 2016).


AVERT. “Syphilis.” (accessed July 13, 2016).

MedlinePlus. “Syphilis.” U.S. National Library of Medicine. (accessed July 13, 2016).

National Institute of Allergy and Infectious Diseases. “Syphilis.” (accessed July 13, 2016).

Planned Parenthood. “Syphilis.” (accessed July 13, 2016).


American Sexual Health Association. PO Box 13827, Research Triangle Park, NC 27709. Telephone: 919-361-8400. Website: (accessed July 13, 2016).

Centers for Disease Control and Prevention. 1600 Clifton Rd., Atlanta, GA 30329-4027. Toll-free: 888-674-6854. Website: (accessed July 13, 2016).

National Women's Health Information Center. 200 Independence Ave. SW, Washington, DC 20201. Toll-free: 800-994-9662. Website: (accessed July 13, 2016).

* paralysis (pah-RAH-luh-sis) is the loss or impairment of the ability to move some part of the body.

* chancre (SHANG-ker) is a usually painless sore or ulcer that forms where a disease-causing germ enters the body, such as with syphilis.

* fetus (FEE-tus) is the term for an unborn human after it is an embryo, from nine weeks after fertilization until childbirth.

* congenital (kon-JEH-nih-tul) means present at birth.

* immune system (im-YOON) is the system of the body composed of specialized cells and the substances they produce that helps protect the body against disease-causing germs.

* bacteria (bak-TEER-ee-a) are single-celled microorganisms which typically reproduce by cell division. Some, but not all, types of bacteria can cause disease in humans. Many types can live in the body without causing harm.

* vaginal (VAH-jih-nul) refers to the canal in a woman that leads from the uterus to the outside of the body.

* oral means by mouth or referring to the mouth.

* anal refers to the anus, the opening at the end of the digestive system through which waste leaves the body.

* vagina (vah-JY-nah) is the canal, or passageway, in a woman that leads from the uterus to the outside of the body.

* rectum is the final portion of the large intestine, connecting the colon to the outside opening of the anus

* lymph nodes (LIMF) are small bean-shaped masses of tissue containing immune system cells that fight harmful microorganisms. Lymph nodes may swell during infections.

* ulcers are open sores on the skin or the lining of a hollow body organ like the stomach or intestine. They may or may not be painful.

* mucous membranes are the thin layers of tissue found inside the nose, ears, cervix (SER-viks) and uterus, stomach, colon and rectum, on the vocal cords, and in other parts of the body.

* genitals (JEH-nih-tuls) are the external sexual organs.

* lesion (LEE-zhun) is a general term referring to a sore or a damaged or irregular area of tissue

* seizures (SEE-zhurs) are sudden bursts of disorganized electrical activity that interrupt the normal functioning of the brain, often leading to uncontrolled movements in the body and sometimes a temporary change in consciousness.

* dementia (dih-MEN-sha) is a loss of mental abilities, including memory, understanding, and judgment.

* paralysis (pah-RAH-luh-sis) is the loss or impairment of the ability to move some part of the body.

* failure to thrive is a condition in which an infant fails to gain weight and grow at the expected rate.

* antibodies (AN-tih-bah-deez) are protein molecules produced by the body's immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.

* stroke is a brain-damaging event usually caused by interference with blood flow to the brain. A stroke may occur when a blood vessel supplying the brain becomes clogged or bursts, depriving brain tissue of oxygen. As a result, nerve cells in the affected area of the brain, and the specific body parts they control, do not properly function.

* neurological (nur-a-LAH-je-kal) refers to the nervous system, which includes the brain, spinal cord, and the nerves that control the senses, movement, and organ functions throughout the body.

  This information is not a tool for self-diagnosis or a substitute for professional care.