Chlamydia

What Is Chlamydia? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Milly Dawson
By Medically Reviewed by 
Reviewed:
Medically Reviewed

Chlamydia is one of the most common sexually transmitted diseases (STDs) in the United States. It’s especially common in young adults, for reasons that have to do with the lifestyle choices made by many young people, such as having sex with many different partners.

While chlamydia can be easily and quickly treated, untreated chlamydia can — and often does — cause infertility in women. Symptoms of chlamydia can be mild or nonexistent, which means it’s important to get screened for it if you fit the recommended screening criteria.

Common Questions & Answers

How do you know if you have chlamydia?
Getting tested is the only way to know for sure whether you have chlamydia. The infection often causes no symptoms, but even when it does, the symptoms are easy to confuse with symptoms of other sexually transmitted diseases or infections that are not sexually transmitted.
What are the first signs of chlamydia?
Often, there are no signs. But among the signs and symptoms that can occur are painful urination and, in women, abdominal pain, vaginal discharge, pain during intercourse, bleeding after intercourse, and bleeding between periods. In men, symptoms may include discharge from the penis and painful testicles.
What happens if you don’t get treated for chlamydia?
Untreated chlamydia can lead to pelvic inflammatory disease (PID) in women and to epididymitis in men. Both conditions are potentially painful and can lead to infertility, and PID raises the risk of an ectopic pregnancy (pregnancy outside the uterus).
How can you tell if a guy has chlamydia?
There’s no way to tell by looking whether a guy has chlamydia. A man (or, indeed, anyone) needs to get tested using an approved laboratory test to know for sure. It’s also important to know that having chlamydia once doesn’t make you immune to it: You can have it an infinite number of times.
Can you die from chlamydia?
Chlamydia itself won’t kill you, but if it damages a woman’s fallopian tubes, leading to an ectopic pregnancy, the fallopian tube can rupture, causing internal bleeding and death if not treated promptly.

Signs and Symptoms of Chlamydia

“The signs of chlamydia are so subtle that women often don’t realize they have an infection,” says Jill Rabin, MD, the co-chief of ambulatory care, OB/GYN, at Northwell Health in Great Neck, New York, and professor of obstetrics and gynecology at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell. And, she emphasizes, usually the disease has no symptoms in women.

For this reason, focusing on signs and symptoms is not especially helpful when it comes to detecting or diagnosing chlamydia.

When symptoms occur, they tend to develop one to three weeks after exposure to chlamydia.

Chlamydia Symptoms in Women

In cases of chlamydia where symptoms occur, women may have one or more of the following symptoms:

  • Pain or a burning sensation while urinating
  • Abnormal vaginal discharge that may be watery or milky
  • Painful discharge or bleeding from the anus
  • Inflamed eyelids (from contact with genital secretions)

Advanced chlamydia may cause additional symptoms in women. The following symptoms indicate that chlamydia infection has spread to the fallopian tubes:

Chlamydia Symptoms in Men

Up to half of all men with chlamydia experience no symptoms. When men do have signs or symptoms, they may be minor and may include one or more of the following:

  • Pain or burning while urinating
  • An abnormal discharge from the penis, which may be pus (a thick yellowish-white fluid) or a watery or milky fluid
  • Painful discharge or bleeding from the anus
  • Inflamed eyelids (from contact with genital secretions)
  • Painful or swollen testicles

Learn More About Symptoms of Chlamydia

Causes and Risk Factors of Chlamydia

Chlamydia is caused by bacteria called Chlamydia trachomatis. These bacteria attack the cells of your body’s mucous membranes — the soft, moist tissues of your body that aren’t covered by skin.

Here are areas of the body where mucous membranes are possible targets for chlamydia infection:

  • Vagina, cervix, and fallopian tubes in women
  • Urethra in women and men
  • Anus and rectum
  • Lining of the eyelid
  • Throat (uncommon)

Chlamydia can be spread through any sexual contact, with or without ejaculation.

Women can also give chlamydia to a baby during childbirth, causing a genital or rectal infection in the infant that may last for a year or longer. Chlamydia can also cause serious eye infections or pneumonia in infants.

Chlamydia trachomatis can also trigger a less common disease in men and women called lymphogranuloma venereum (LGV). LGV can cause painless genital ulcers, enlarged groin lymph nodes, and/or inflammation of the anus and rectum.

Chlamydia Risk Factors

While chlamydia can be spread through any sexual contact involving mucous membranes, certain activities — and certain people — are more likely to spread the infection.

Chlamydia is more likely to spread through genital-to-genital contact than from your mouth to someone’s penis, vagina, or anus, or from any of these areas to your mouth. That’s because the bacteria thrive in these other areas more easily than in your mouth or throat.

Young people are especially likely to get chlamydia, for a combination of behavioral and cultural reasons. Not using condoms consistently, moving quickly from one sexual relationship to another, and lack of access to STD screening services may all contribute to this increased risk.

In addition, young people may be more vulnerable because “those young cells tend to attract the agents that cause chlamydia and other STDs, such as HPV [human papillomavirus], a bit more vigorously,” says Dr. Rabin.

Men who have sex with men are also considered to be at increased risk for chlamydia. In this group, the rate of positive chlamydia test results from a rectal swab ranges from 3.0 to 10.5 percent, and the rate from throat swabs ranges from 0.5 to 2.3 percent.

If you’re treated for chlamydia but your sexual partner isn’t, you can be reinfected by your partner, even if your partner is asymptomatic.

How Is Chlamydia Diagnosed?

There are a few different types of diagnostic tests for chlamydia. The newest type, known as nucleic acid amplification tests (NAATs), can easily be performed on a swab of your vagina or a urine sample. Vaginal swabs are the preferred method to test for genital chlamydia in women, while urine samples are preferred for men.

The U.S. Food and Drug Administration has approved NAATs for use on urogenital and extragenital sites, including urine, endocervical, vaginal, male urethral, rectal, and pharyngeal specimens.

Who Should Get Tested for Chlamydia?

If you’re a sexually active woman under age 25, the CDC recommends getting a yearly test for chlamydia and other STDs. Annual testing is also recommended for women age 25 and older if they have multiple sexual partners, a new sex partner, or a sex partner with multiple partners or who gets an STD.

Pregnant women should be screened for chlamydia according to the above guidelines, with a second test during the third trimester of pregnancy. If a pregnant woman tests positive for chlamydia, she should be tested again four weeks after treatment to ensure that it was effective, and again in three months.

Men who have sex with men should also get screened for chlamydia yearly, with any potential areas of contact — urethra, rectum, or throat — included in these tests, regardless of whether condoms were used. Men in this group with multiple sex partners, or whose partner has multiple partners, should get tested every three to six months instead.

People with HIV should be tested for chlamydia at their first HIV evaluation, and at least once a year after that if they’re sexually active, depending on their sexual practices.

Notifying Sexual Partners

If you test positive for chlamydia, you should communicate this result to all sexual partners with whom you were intimate in the 60 days before the onset of symptoms or before your diagnosis — whichever is earlier. This recommendation applies to partners of all genders, with whom you’ve had anal, oral, or vaginal sex.

In some states, your healthcare provider is allowed to prescribe extra doses of antibiotics for you to give to your sexual partners — a practice known as expedited partner therapy (EPT). This practice has been shown to reduce the rate of chlamydia reinfection in the original person seeking treatment, as well as increase the reported rate of sexual partners getting treatment.

Prognosis of Chlamydia

“Chlamydia can be cured easily if it’s caught early,” Rabin says. If you receive prompt treatment with antibiotics, you can avoid the most damaging effects of chlamydia, such as severe pain or infertility in women.

If chlamydia isn’t promptly detected and treated, on the other hand, it can lead to a number of potentially serious complications.

Duration of Chlamydia

If you become infected with chlamydia, any initial symptoms may occur one to three weeks after the time of infection. But in many people who test positive for chlamydia, there are no symptoms, and it’s impossible to pin down how long they’ve had the infection.

Chlamydia doesn’t go away on its own without treatment. If you don’t get treated, you may develop serious symptoms or complications.

Treatment and Medication Options for Chlamydia

A course of antibiotics is the treatment for chlamydia. Your doctor will decide which drug to prescribe, and at what dose, according to your individual medical needs and other aspects of your situation.

It’s important to abstain from having sex until seven days after the start of your antibiotic treatment, to prevent the transmission of chlamydia to a sexual partner. If you have a partner who is being treated for chlamydia, the same recommendation applies to them.

If you have symptoms that persist for more than a few days after you start your treatment, see your doctor again to be reevaluated.

Because the symptoms of chlamydia are similar to those of gonorrhea, you should be treated for both infections if you test positive for chlamydia. That’s because it’s often faster and cheaper to just treat both infections than to order another test for gonorrhea after a positive test result for chlamydia.

After completing your antibiotic treatment for chlamydia, you’ll need to get tested again after three to four months — or earlier, if recommended — to check for reinfection.

While antibiotics can cure chlamydia, they can’t reverse any permanent damage caused by the infection.

Medication Options

For adults and adolescents, the most common antibiotic regimens prescribed to treat chlamydia are as follows, taken by mouth:

Alternative drugs that may be considered for special situations include the following:

In some cases, including for some pregnant women, a lower dose of antibiotics may be taken up to four times a day, for as long as 14 days.

Learn More About Chlamydia Treatment and Prevention

Prevention of Chlamydia

There are a few steps you can take to reduce or eliminate your risk of getting chlamydia.

The only sure way to avoid chlamydia is to abstain from having vaginal, anal, or oral sex. You’re also highly unlikely to get chlamydia if you’re in a long-term monogamous relationship with a partner who has tested negative for the disease.

In other cases, using latex male condoms — correctly and consistently — can reduce your risk of getting chlamydia and other STDs. There isn’t enough data on preventing chlamydia transmission with other barrier methods (such as female condoms) for the CDC to recommend them.

Complications of Chlamydia

If left undiagnosed and untreated, chlamydia can lead to serious complications in both women and men.

In women, untreated chlamydia can lead to the following complications:

PID, a serious infection of the reproductive organs, occurs with symptoms in about 10 to 15 percent of women with untreated chlamydia. But with or without symptoms, it can cause permanent damage to the fallopian tubes, uterus, and surrounding tissues, potentially resulting in chronic pelvic pain, infertility, or ectopic pregnancy (a sometimes fatal condition).

Cervicitis can sometimes cause a yellowish discharge from the cervix.

In men, untreated chlamydia can lead to the following complications:

Prostatitis can come on gradually or suddenly, potentially causing severe pain.

In both women and men, chlamydia can increase the risk of HIV infection if you’re exposed to the virus.

Research and Statistics: How Many People Get Chlamydia?

Chlamydia is a very common infection, constituting the largest proportion of all STDs reported to the CDC since 1994.

In 2020, there were nearly 1.6 million reported cases of chlamydia in the United States, a decrease of 13 percent compared with 2019, which may be attributed not to fewer cases but fewer in-person doctor visits during the pandemic. This comes out to about 481 cases per 100,000 people, but many experts believe that the actual number of infections is much higher.

The American Sexual Health Association (ASHA), for instance, estimates that as many as 3 million people have chlamydia each year in the United States.

Young people are more likely to get chlamydia than the general population. For both women and men, incidence rises and peaks in their late teens and early 20s. For example, the rate of reported chlamydia in 2020 was nearly 4,800 cases per 100,000 women ages 19 and 20. Among men, incidence peaks at ages 19 and 20 at just over 1,800 cases per 100,000 people.
The rate of reported chlamydia varies widely throughout the United States at the county and state level. In 2020, Vermont, New Hampshire, and Maine had the lowest reported rates of chlamydia, while the highest rates were found in the Mississippi, Louisiana, and Alaska. The region with the highest rate of chlamydia was the South, while the Northeast had the lowest rate.

Racial Disparity and Chlamydia

The prevalence of chlamydia is drastically different across racial and ethnic groups in the United States. Overall, Black, white, and Hispanic women have the highest rates of chlamydia.

In 2020, there were nearly 447,000 reported cases of chlamydia among Black Americans, with around 352,000 for white Americans and nearly 189,000 for Hispanic Americans. The lowest rates were among Native Hawaiian/Pacific Islanders, at 3,384 reported cases, and American Indian/Alaska natives, at 14,917.


Related Conditions

Gonorrhea This bacterial infection can cause symptoms and complications similar to those of chlamydia.

Genital Herpes This viral infection is common, but most people with genital herpes don’t know they have it.

Human Papillomavirus (HPV) The most common STD in the United States, this viral infection can cause genital warts and lead to cervical and other cancers. Many forms of HPV can be prevented by vaccines.

HIV/AIDS People who have other STDs are at increased risk for HIV infection, which is largely preventable through pre-exposure prophylaxis (PrEP) therapies.

Sexual Health Resources

You can protect your sexual health and fertility by educating yourself about STDs, as well as about healthy relationships and sexuality. If you’re sexually active, you should also get screened for STDs, according to CDC guidelines.

The following resources can help provide information, support, and services related to sexual health.

Centers for Disease Control and Prevention

This online resource from the leading public health agency in the United States provides an overview of numerous STDs and related conditions, covering areas including prevention, testing, treatment, and statistics.

American Sexual Health Association

This nonprofit organization has online resources covering a wide range of topics, including STDs, sexual anatomy, sexual health in relationships, and talking to your kids about sex. It also has an online support group and discussion community with areas for specific STDs, STD prevention, and emotional and relationship issues.

National Coalition for Sexual Health

This coalition of more than 120 member organizations supports improving sexual health for all Americans by promoting high-quality sexual health information and health services. Its website has resources for the public and for healthcare providers, on topics like preventive health services, sexual health quick tips, and how to discuss sexual health at a doctor’s appointment.

Office on Women’s Health

This division of the U.S. Department of Health and Human Services provides information on numerous topics related to sexual and reproductive health, including STDs, relationships and safety, breastfeeding, and much more.

Planned Parenthood

This nonprofit organization operates clinics throughout the United States that provide STD testing and treatment, birth control, emergency contraception, abortion, and other sexual health services.

Learn More About Sexual Health Resources

Additional reporting by Quinn Phillips.

Editorial Sources and Fact-Checking

Show Less