Chlamydia is one of the most common sexually transmitted infections (STIs) in the United States and worldwide. If you’re worried about chlamydia or just want to learn more, you’re in the right place. This guide covers everything you need to know—from symptoms and testing to treatment and prevention. The good news is that chlamydia is easily treated with antibiotics, but catching it early is important since untreated infections can lead to serious health problems. Let’s dive into the essential facts about chlamydia in clear, straightforward language.

What Is Chlamydia?

Chlamydia is a common bacterial infection caused by the bacterium Chlamydia trachomatis (C. trachomatis). It spreads through sexual contact and can affect both men and women of any age, though it’s most common among younger people. The infection can happen in the genitals, rectum, or throat, depending on the type of sexual contact.

Chlamydia trachomatis bacteria

 

What makes chlamydia tricky is that most infected people don’t show any symptoms at all. That’s why it’s sometimes called a “silent” infection. Even without symptoms, the bacteria can still damage your body and can be passed to sexual partners.

Chlamydia is especially concerning because if left untreated, it can cause serious health problems. For women, untreated chlamydia can cause permanent damage to the reproductive system, making it difficult or impossible to get pregnant later. It can also cause a dangerous condition called ectopic pregnancy, where a pregnancy develops outside the womb.

Chlamydia Symptoms

As mentioned, chlamydia often causes no symptoms at all. In fact, about 75% of women and 50% of men with chlamydia don’t notice any signs of infection. But that doesn’t mean the infection isn’t causing damage or can’t be spread to others.

When symptoms do appear, they usually show up several weeks after exposure to the chlamydia bacteria. The specific symptoms depend on the person’s sex and where in the body the infection is located.

Chlamydia Symptoms chart

Symptoms in Men

Men who develop symptoms of chlamydia might notice:

  • Discharge from the penis—this could be cloudy or clear
  • A burning sensation when urinating
  • Pain and swelling in one or both testicles (though this is less common)
  • Rectal pain, discharge, or bleeding (if the infection is in the rectum)

Symptoms in Women

For women who develop symptoms, they might include:

  • Abnormal vaginal discharge that may have an unusual odor
  • A burning sensation when urinating
  • Pain during sex
  • Bleeding between periods or after sex
  • Lower abdominal pain
  • Rectal pain, discharge, or bleeding (if the infection is in the rectum)

Women need to be especially vigilant about getting tested for chlamydia even without symptoms. This is because untreated chlamydia in women can silently spread to the reproductive organs, causing pelvic inflammatory disease (PID), which can lead to chronic pelvic pain, infertility, and ectopic pregnancy.

Chlamydia Statistics

The numbers tell a compelling story about how common chlamydia is and who it affects most. In 2020, there were an estimated 128.5 million new chlamydia infections globally among adults aged 15-49. That’s a staggering number that highlights how widespread this infection is.

In the United States, chlamydia continues to be the most commonly reported bacterial STI. Looking at the data from 2023 from the CDC, the highest rates of chlamydia were reported in young adults aged 20-24 years.

Chlamydia Cases in the United States

 

Why are young people and women more affected? There are several reasons:

  1. Biological factors: Young women’s cervical cells are more vulnerable to infection.
  2. Screening practices: Women are more likely to be screened during routine gynecological care.
  3. Social factors: Young people may be more likely to have multiple partners or inconsistent condom use.

How Do You Get Chlamydia?

Chlamydia spreads primarily through sexual contact. Understanding exactly how transmission occurs can help you better protect yourself and your partners. The main ways chlamydia spreads include:

  • Vaginal sex: Having vaginal intercourse with an infected partner is a common way to transmit chlamydia.
  • Anal sex: The rectum can become infected through receptive anal sex.
  • Oral sex: Though less common, chlamydia can spread through this way, leading to throat infections.
  • From mother to baby: A pregnant woman with chlamydia can pass the infection to her baby during childbirth.
  • Manual sex: Though rare, touching genitals and then your eyes can spread the bacteria.

How Do You Prevent Chlamydia?

Preventing chlamydia involves a combination of safe sex practices, open communication, and regular testing. Here are effective strategies to reduce your risk:

Use Condoms Correctly and Consistently

Condoms are one of the best ways to prevent chlamydia and other STIs. For effective protection:

  • Use a new condom for every sex act.
  • Put the condom on before any genital contact.
  • Make sure to use them for vaginal, anal, and oral sex.
  • Store condoms in a cool, dry place.
  • Check the expiration date.

Get Regular STI Testing

Regular testing is essential, especially if you’re sexually active with multiple sex partners, especially if you have had unprotected sex. The CDC recommends:

  • Annual chlamydia screening for all sexually active women under 25
  • Annual screening for older women with risk factors (new partner, multiple partners)
  • Regular screening for men who have sex with men
  • Testing for anyone with symptoms or whose partner has been diagnosed

Limit Sexual Partners

Having fewer sexual partners reduces your exposure risk. If you do have multiple partners, consistent condom use becomes even more important.

Talk Openly With Partners

Have honest conversations about sexual health before intimacy. Ask about testing history and discuss using protection. While these conversations can feel awkward, they’re an important part of taking care of your health and showing respect for your partners.

Get Treated Quickly If Exposed

If you find out a partner has chlamydia, get tested and treated right away. Prompt treatment prevents complications and breaks the chain of transmission.

Practice Good Hygiene

While chlamydia isn’t spread through casual contact, practicing good hygiene is always important for overall sexual health:

  • Urinate soon after sex
  • Wash genitals with mild soap and water
  • Never share sex toys without thoroughly cleaning them or using a new condom

By combining these strategies, you can significantly reduce your risk of contracting chlamydia and other STIs.

Chlamydia Treatments

If you test positive for chlamydia, don’t panic. The infection is highly treatable with antibiotics. The sooner you start treatment, the better—untreated chlamydia can cause serious complications and be spread easily to others.

Standard Treatment Options

The CDC recommends these treatments for uncomplicated chlamydia infections:

  • Doxycycline: 100 mg taken orally twice daily for 7 days

    OR

  • Azithromycin: 1 gram (1000 mg) taken orally in a single dose

In some cases, your doctor might prescribe:

  • Levofloxacin: 500 mg taken orally once daily for 7 days

Important Treatment Guidelines

When taking antibiotics for chlamydia:

  1. Take all medication as prescribed: Even if symptoms go away, finish all the pills to make sure the infection is completely cleared.
  2. Abstain from sex during treatment: To avoid spreading the infection, don’t have sex until you’ve completed the full course of antibiotics.
  3. Get partners treated: All recent sexual partners should be notified, tested, and treated to prevent reinfection.
  4. Get retested: In some cases, doctors recommend getting retested three months after treatment to ensure the infection is gone.

Treatment During Pregnancy

If you’re pregnant and have chlamydia, treatment is especially important to prevent passing the infection to your baby during birth. Pregnant women are typically treated with azithromycin, as doxycycline isn’t recommended during pregnancy.

After Treatment

After completing treatment:

  • Wait 7 days after finishing single-dose therapy or after completing a 7-day course before having sex again.
  • Make sure your partner(s) get treated to prevent reinfection.
  • Consider getting retested in 3 months, especially if you’re under 25 or at high risk for reinfection.
  • Adopt prevention strategies to avoid future infections.

FAQs

Can you get chlamydia if you’ve never had sex?

While chlamydia is primarily transmitted through sexual activity, in rare cases, it can be transmitted through non-sexual means. Newborns can get chlamydia during birth if their mother is infected. Additionally, if someone touches infected genital fluids and then touches their eyes, they could develop a chlamydial eye infection. However, you cannot get chlamydia from toilet seats, sharing towels, or hugging.

How long after exposure do chlamydia symptoms appear?

If symptoms occur, they typically appear 1-3 weeks after exposure to the bacteria. However, it’s important to remember that most chlamydia infections (up to 75% in women and 50% in men) cause no symptoms at all.

Can you get chlamydia from oral sex?

Yes, chlamydia can be transmitted in this way. If you give oral sex to a partner with a genital chlamydia infection, you can develop a chlamydial infection in your throat. Similarly, receiving oral sex from someone with a throat infection could lead to a genital infection. While less common than transmission through vaginal or anal sex, oral transmission is still possible.

Does chlamydia go away on its own?

Some studies suggest that in a small percentage of cases, the body may clear a chlamydia infection without treatment. However, there’s no reliable way to know if this will happen in any particular case. Waiting to see if an infection clears on its own is risky because:

  • The infection could cause permanent damage while you wait
  • You might spread the infection to others
  • The longer an infection remains untreated, the greater the risk of complications

For these reasons, medical experts always recommend antibiotic treatment for chlamydia rather than waiting.

How effective are condoms at preventing chlamydia infection?

When used correctly and consistently, condoms are highly effective at preventing the transmission of chlamydia. Research shows that among people with known exposure to chlamydia, consistent condom users had a significantly lower infection rate (13.3%) compared to inconsistent users (34.4%). This represents a 90% reduction in risk compared to unprotected sex. However, condoms must be used for all forms of sexual intercourse (vaginal, anal, oral) to provide protection.

How often should I get tested for chlamydia?

The CDC recommends annual chlamydia screening for:

  • All sexually active women under age 25
  • Women 25 and older with risk factors (new partner, multiple partners)
  • Men who have sex with men (at sites of contact – urethra, rectum, throat)
  • Anyone whose partner has been diagnosed with an STI

More frequent testing (every 3-6 months) may be recommended for those with multiple partners or other high-risk behaviors. You can do this privately or at home.

Sources

  1. CDC. About Chlamydia. (2025). https://www.cdc.gov/chlamydia/about/index.html
  2. Wikipedia. Chlamydia. https://en.wikipedia.org/wiki/Chlamydia
  3. Wikipedia. Chlamydia trachomatis. https://en.wikipedia.org/wiki/Chlamydia_trachomatis
  4. World Health Organization. Chlamydia. (2024). https://www.who.int/news-room/fact-sheets/detail/chlamydia
  5. Warner L, et al. Condom effectiveness for prevention of Chlamydia trachomatis infection. (2005). https://sti.bmj.com/content/81/4/323.short
  6. CDC. Chlamydial Infections – STI Treatment Guidelines. (2021). https://www.cdc.gov/std/treatment-guidelines/chlamydia.htm
  7. Martin DH, et al. Doxycycline and azithromycin for prevention of chlamydial persistence or recurrence. (1998). https://pubmed.ncbi.nlm.nih.gov/9437777/