This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

Chlamydia is one of the most common bacterial infections that spread through sex. It is also one of the easiest to treat. The hard part is that most people who have it feel fine, so the only way to find out is a test.

This guide explains the symptoms of chlamydia, who should be screened, how testing works, whether chlamydia is curable, what chlamydia treatment looks like, and what to do about partners. It also covers what is different about getting tested in Chicago.

Key takeaways

Most people with chlamydia have no symptoms, according to the CDC. A test is the only way to know.
The USPSTF and the CDC recommend yearly screening for sexually active women 24 and younger, and for older women with risk factors. The CDC also recommends at least yearly screening for sexually active gay, bisexual and other men who have sex with men.
Testing is usually a urine sample or a swab, run as a nucleic acid amplification test (NAAT).
Chlamydia is curable with antibiotics that a clinician prescribes. Treatment is not something to guess at or borrow from someone else.
The CDC recommends retesting about three months after treatment, even when partners were treated too.
Illinois permits expedited partner therapy (EPT) for chlamydia, so a clinician may be able to provide treatment for a partner without a separate visit.
Chicago has several walk-in and low-cost options, including city sexual health clinics, Cook County Health and Howard Brown Health.

What this guide covers

What chlamydia is and how it spreads
Symptoms of chlamydia
Who should be tested, and how often
How chlamydia testing works
Is chlamydia curable? Treatment and retesting
Partners, Illinois EPT and prevention
Chlamydia in Chicago: data, clinics and your rights
Common questions

What chlamydia is and how it spreads

Chlamydia is an infection caused by the bacterium Chlamydia trachomatis. The CDC describes it as one of the most commonly reported bacterial sexually transmitted infections in the United States.

Because it is a bacterial infection, it responds to antibiotics. That is the main reason testing matters. A found infection can be treated, and a missed one can linger.

How it spreads

According to the CDC, chlamydia passes through vaginal, anal or oral sex with a person who has the infection. It can pass even when no one ejaculates. It can also pass from a pregnant person to a baby during delivery.

Anyone who has sex can get chlamydia. It is not a sign of anything about a person's character, and it has nothing to do with gender or orientation. It is an infection, and infections are treated like any other.

Where in the body it can be found

Chlamydia can infect the cervix, urethra, rectum, throat and eyes. Which sites matter for you depends on the kinds of sex you have. This is why the CDC guidelines ask clinicians to think about exposure sites and not only about who a person is.

A person can have an infection in one site and a negative result at another. If you have had oral or anal sex, tell the clinician so they can test the right places.

Symptoms of chlamydia

The CDC says most people with chlamydia have no symptoms. When symptoms do appear, they may show up weeks after exposure, or they may never show up at all.

Neither the presence nor the absence of symptoms can tell you whether you have chlamydia. Only a test can. That is the central point of this whole guide.

Possible symptoms in people with a vagina or cervix

Unusual vaginal discharge
Burning when urinating
Bleeding between periods or after sex
Pain in the lower belly or during sex

Possible symptoms in people with a penis

Discharge from the penis
Burning when urinating
Pain or swelling in one or both testicles

Possible symptoms in the rectum or throat

The CDC notes that rectal chlamydia may cause pain, discharge or bleeding, though it often causes nothing. Throat infections usually cause no symptoms. A sore throat alone does not point to chlamydia, and many other things cause it.

Why symptoms are not a reliable guide

Several other infections cause the same discomforts. Gonorrhea, trichomoniasis, urinary tract infections and yeast infections can all overlap with the list above. A clinician cannot sort them out by looking, and neither can you.

If you notice any of these changes, a visit and a test are the next step. If you notice nothing and have had a new partner or a partner with an infection, a test is still worthwhile.

What happens when chlamydia goes untreated

Untreated chlamydia can cause lasting problems, according to the CDC. In people with a cervix, the infection can spread to the uterus and tubes and cause pelvic inflammatory disease (PID). PID can lead to chronic pelvic pain, ectopic pregnancy and difficulty getting pregnant.

In people with a penis, the infection can spread to the epididymis, the tube beside the testicle, and cause pain and swelling. Reactive arthritis is a rarer complication. A baby born to a person with untreated chlamydia can develop an eye infection or pneumonia.

These outcomes are the reason screening exists. Most are preventable when the infection is found and treated early.

Who should be tested, and how often

Because symptoms are unreliable, screening guidelines focus on groups with higher chances of infection. They apply whether or not you feel anything.

The USPSTF and CDC recommendations

The U.S. Preventive Services Task Force (USPSTF) recommends screening for chlamydia in sexually active women 24 years and younger, and in older women who are at increased risk. The CDC 2021 STI Treatment Guidelines make the same recommendation and add more detail:

Sexually active women under 25: screening at least once a year.
Older women with risk factors: yearly screening. Risk factors include a new partner, more than one partner, or a partner who has other partners or an STI.
Pregnant people: the CDC recommends screening at the first prenatal visit for those under 25 and for older people at increased risk, with retesting in the third trimester for those who remain at risk.
Gay, bisexual and other men who have sex with men: at least yearly screening at the sites of exposure. The CDC suggests more frequent screening, every three to six months, for those with higher chances of exposure.
Transgender and nonbinary people: the CDC advises screening based on the anatomy a person has and the kinds of sex they have, using the same guidance that applies to that anatomy.
People with HIV: screening at the first visit and at least yearly after that.

When to test outside a routine schedule

Beyond those groups, a test makes sense in several situations:

A new partner, or a partner who has other partners.
A partner who tells you they were diagnosed with chlamydia or another STI.
Any symptom described above.
Before stopping condom use with a new partner.
You simply want to know your status.

Timing after an exposure

People often ask how soon after sex a test will work. The CDC treatment guidelines do not give one single waiting period for chlamydia that applies to every person and every test. Because of that, a clinician is the best person to advise you on timing.

If you are worried about a recent exposure, say so when you call or arrive. A clinician may test right away, suggest a repeat visit later, or offer treatment based on the exposure. That is a decision made with you, not for you.

How chlamydia testing works

The CDC recommends nucleic acid amplification tests, called NAATs, for chlamydia. A NAAT looks for the genetic material of the bacterium. It is the most sensitive type of test available.

What the sample looks like

Urine: a first-catch urine sample, which means the first part of the stream.
Vaginal swab: the CDC lists this as the preferred sample for people with a vagina. It can often be collected by the patient in private.
Rectal or throat swab: used when those sites have been exposed. A clinician can explain how this is done, and in many clinics you collect your own sample.

A routine blood test does not detect chlamydia. If you had blood drawn at a visit, that does not mean you were tested for it.

What to expect at a visit

A clinic visit for STI testing usually takes a short history, a sample, and a plan for getting results. You can be asked about the kinds of sex you have, how many partners, and whether you have symptoms. Those questions are there to choose the right tests, not to judge.

Clinicians often test for several infections at once. Chlamydia and gonorrhea are commonly tested together, and a visit may also include HIV, syphilis and hepatitis screening. Ask what is being tested so you know what the results cover.

Understanding your result

A positive result means the test found the bacterium. A negative result means it did not find it in the sample taken. Neither replaces the advice of a clinician who knows your history, and a recent exposure can affect how a result is read.

If your result is positive, the clinic will talk with you about treatment. A positive result is common, treatable and not a reason for shame.

Reporting

Chlamydia is a reportable infection in Illinois. The Illinois Administrative Code (77 Ill. Adm. Code Part 693) says health care professionals must report it within seven days of diagnosis or treatment, and in Chicago those reports go to the local health department. Reporting is how public health staff track trends and arrange partner services. It is a routine step, not a punishment.

Is chlamydia curable? Treatment and retesting

Yes. Chlamydia is curable. The CDC states that it can be cured with the right antibiotics. This is a major difference from infections such as HIV, herpes and HPV, which are treatable or manageable but not curable.

The important word is prescribed. Chlamydia treatment is something a clinician decides on and prescribes. This guide does not list doses or schedules, and you should not use leftover medicine or a friend's medicine.

What chlamydia treatment looks like

The CDC 2021 STI Treatment Guidelines name doxycycline as the recommended antibiotic for most people. Azithromycin is an alternative a clinician may choose in some situations. Which medicine you are given, and for how long, depends on your health, other medicines, allergies and whether you are pregnant. The clinician who prescribes it will explain how to take it.

Pregnancy changes the choice. The CDC guidelines recommend a different antibiotic option for pregnant people, so tell the clinic if you are pregnant or might be.

If the clinic is concerned about complications such as PID, or if the infection involves the rectum in a way that raises other concerns, the plan may be different. Your clinician will tell you what applies.

Finishing treatment and pausing sex

Take the full prescription as directed, even if symptoms fade quickly. The CDC advises avoiding sex until treatment is complete and for a week after, and until partners have also been treated. This helps prevent passing the infection back and forth.

If symptoms continue after treatment, contact the clinic. Ongoing symptoms can have other causes, or can mean the infection came back from a partner who was not treated.

Retesting at three months

The CDC recommends retesting about three months after treatment. This is not because treatment usually fails. It is because getting chlamydia again is common, often from an untreated partner or a new one, and repeat infections raise the risk of complications such as PID.

If you cannot test at three months, the CDC advises testing whenever you next see a clinician within the first year after treatment.

A "test of cure" soon after treatment is not routine for most people. The CDC guidelines do advise retesting in pregnancy, and a clinician will tell you when. Testing too soon after treatment can also pick up leftover genetic material from bacteria that are no longer alive, which can confuse the result.

Does having had chlamydia protect you?

No. Having chlamydia once does not make you immune. You can get it again after being cured. That is another reason the three-month retest matters.

Newer prevention: doxy-PEP

In 2024 the CDC issued guidance on doxycycline taken after sex as post-exposure prophylaxis, often called doxy-PEP. The guidance is aimed at gay, bisexual and other men who have sex with men, and transgender women, who have had a bacterial STI in the past year. The CDC says doxy-PEP can lower the chance of chlamydia and syphilis, with less benefit shown for gonorrhea. It does not protect against HIV or other viruses.

Doxy-PEP is a prescription decision made with a clinician. The Illinois Department of Public Health lists doxy-PEP guidance and a fact sheet on its STD page, and Howard Brown Health offers it by appointment.

Partners, Illinois EPT and prevention

Telling partners

If you test positive, the CDC advises that recent sex partners be told so they can be tested and treated. Recent usually means partners in the 60 days before symptoms started or before the test, and a clinician can help you work out who that includes. If your last partner was longer ago, they should still be told.

This conversation is hard for many people. You can keep it short and factual: you tested positive for chlamydia, it is treatable, and they should get tested. The clinic or the health department can often help with notifying partners without naming you.

Expedited partner therapy in Illinois

Expedited partner therapy (EPT) means a clinician can give treatment or a prescription for a patient's partner without examining that partner first. The CDC's page on the legal status of EPT in Illinois says it is permissible for chlamydia, gonorrhea and trichomoniasis. It is not covered for syphilis.

The Illinois Sexually Transmitted Infection Control Act (410 ILCS 325/6) limits EPT to partners exposed within the previous 60 days, and it requires counseling and written materials from the Illinois Department of Public Health for the partner. The CDC page reflects the law as of January 1, 2022, and it was updated in August 2024.

Ask your clinician whether EPT is an option for you. It is not guaranteed at every visit, and partners should still see a clinician when they can, especially if they are pregnant, have symptoms or have other health concerns.

Ways to lower your chances of chlamydia

Condoms and dental dams, used correctly, lower the chance of getting or passing chlamydia, according to the CDC.
Regular testing, matched to the guidance above, finds infections early.
Talking with partners about testing before sex helps everyone.
Not sharing and not reusing sex toys without cleaning them, or using a new condom on them, helps too.
For some people, doxy-PEP is an option to discuss with a clinician.

Prevention is a set of choices, and no one measure removes all chances of infection. Combining them helps.

Chlamydia in Chicago: data, clinics and your rights

What the local numbers show

The Illinois Department of Public Health (IDPH) reports that the City of Chicago had 27,596 chlamydia cases in 2022, a rate of 1,023.7 per 100,000 people. These come from IDPH's reported STI cases and rates by county table for 2018 to 2022, and IDPH notes it calculates rates using 2010 Census population.

For comparison, the CDC's 2023 state ranking tables list Illinois at 557.7 chlamydia cases per 100,000 people (69,992 cases), 11th among states. Those two figures are from different years and use different population bases, so they should not be treated as a direct comparison.

What these numbers do show is that chlamydia is common in Chicago. Reported cases reflect who was tested, so higher counts partly reflect more testing. They are a reason to screen routinely, not a reason for fear.

Where to get tested

Chicago has several kinds of testing sites. Hours and walk-in rules change, so call before you go. For a fuller list with costs, see our guide to STD testing in Chicago. The CDC's GetTested locator at gettested.cdc.gov can also help you find sites by ZIP code.

Chicago Department of Public Health sexual health clinics

The Chicago Department of Public Health (CDPH) runs sexual health specialty clinics that offer STD testing, HIV testing, PrEP and treatment. CDPH's page says to call for an appointment, that limited walk-ins are available, and that the clinics close from 12 to 1 pm daily and on City holidays. It also says to call the clinic to verify hours.

Lakeview, North Clark Street Health Clinic: 2849 N. Clark St., 1st Fl. Phone 312.744.5507. Monday, Wednesday and Friday 8:00 am to 4:00 pm; Tuesday and Thursday 9:00 am to 5:00 pm.
Austin, West Division Street Health Hub: 4909 W. Division St., Suite 411. Phone 312.746.4871. Tuesday 9:00 am to 5:00 pm; Wednesday and Friday 8:00 am to 4:00 pm.
Roseland, East 115th Street Health Hub: 200 E. 115th St., 1.5 fl. Phone 312.747.1090. Monday and Friday 8:00 am to 4:00 pm; Thursday 9:00 am to 5:00 pm.

On cost, CDPH says care is provided regardless of ability to pay or insurance status, and asks insured patients to bring an insurance card. The page does not say the visit is free, so ask the clinic about charges when you call.

Cook County Health: Ruth M. Rothstein CORE Center

Cook County Health's page for the CORE Center, at 2020 W. Harrison St., Chicago, IL 60612, lists a walk-in STI Screening Clinic. It says to call Monday through Friday, 8:30 am to 3:30 pm, and that same-day HIV and STI services are provided. The number is 312-572-4700. Appointments go through the Access Line at 312-572-4500.

The CDC's GetTested listing for this site shows that it accepts insurance, Medicaid and Medicare, offers a sliding scale, and has PrEP for the uninsured.

Howard Brown Health

Howard Brown Health is a nonprofit health center that runs a sexual health walk-in clinic. Its page says no appointment is necessary and that patients are seen first come, first served. The page lists testing and treatment for chlamydia, gonorrhea and syphilis, along with HIV and hepatitis testing, PEP and PrEP. Howard Brown describes the clinic as quick and low-cost, and offers a Sliding Fee Discount Program based on income and family size. The phone number for all locations is 773.388.1600.

Sheridan: 4025 N. Sheridan Rd., Chicago, IL 60613.
63rd Street: 641 W. 63rd St., Chicago, IL 60621.
Broadway Youth Center: 1023 W. Irving Park Road, Chicago, IL 60613. Howard Brown describes its youth services as for ages 12 to 24.

Howard Brown offers doxy-PEP by appointment. It is not listed as a walk-in service.

Planned Parenthood of Illinois, Rogers Park

The CDC's GetTested locator lists the Planned Parenthood of Illinois Rogers Park Health Center at 5725 N Broadway, Chicago, IL 60660, phone (773) 942-7193. The listing says an appointment is required and that insurance and Medicaid are accepted. It does not state whether a sliding scale is offered, so ask when you call. GetTested also notes that hours of operation may change.

Home testing

Erie Family Health Centers, a Chicago nonprofit health center, offers a free rapid HIV test kit by online request or by phone at 312-386-6344. It is for Illinois residents who are 17 or older, and it tests for HIV only. It does not test for chlamydia. No free state or city mail-order chlamydia test program was found, so check with the health department if you want to know whether one exists.

Your rights and privacy in Illinois

Under the Illinois Consent by Minors to Health Care Services Act (410 ILCS 210/4), a minor 12 years of age or older who may have come into contact with a sexually transmitted disease can consent to health care services or counseling related to prevention, diagnosis or treatment. Parental consent is not necessary. The law also says providers shall make reasonable efforts to involve the family if they believe it will not be detrimental to the minor, and that each STD incident is reported to public health.

If you are a teen, you can ask the clinic what that means in practice before your visit.

Pregnancy and syphilis screening

Chlamydia screening in pregnancy follows the CDC guidance above. Illinois law (410 ILCS 320/1, the Prenatal Syphilis Act) separately requires syphilis testing at the first prenatal exam and again in the third trimester, between 27 and 32 weeks. Chlamydia testing during pregnancy is a clinical decision made with your prenatal provider, so ask your clinician which tests are part of your care.

Who to call with questions

The Illinois HIV/STD Hotline is 1-800-243-2437, listed on the IDPH STD page. The Chicago Department of Public Health also has information on its main site.

Common questions

Can chlamydia go away on its own?

It should not be left to chance. The CDC treats chlamydia with antibiotics because untreated infection can cause complications. A clinician can tell you what makes sense for you.

Is chlamydia curable if I have had it more than once?

Yes. A repeat infection is treated again with clinician-prescribed antibiotics. Repeat infections are common, which is why the CDC recommends retesting about three months after treatment.

Will my partner know if I get tested?

A clinic does not tell your partners about your results. Chlamydia is reportable to the health department, which can offer help notifying partners if you want it. Ask the clinic how your information is handled before you give it.

Can I get chlamydia from a toilet seat or a hug?

The CDC lists sexual contact as the way chlamydia spreads. It does not spread through hugging, sharing food or sitting on toilet seats.

Can chlamydia be in my throat?

Yes, after oral sex with a person who has the infection. It usually causes no symptoms, which is why exposure sites matter when you are tested.

Does chlamydia affect fertility?

Untreated chlamydia can lead to PID, which is a known cause of fertility problems for people with a uterus, according to the CDC. Early treatment lowers that risk. If you are planning a pregnancy, ask your clinician about screening.

What if I cannot afford a visit?

Start with the options above. CDPH says care is provided regardless of ability to pay, Howard Brown has a sliding fee program, and the CORE Center lists a sliding scale. Costs and rules can change, so confirm by phone.

What should I do next?

If you are due for screening, or you have had a new partner, call one of the clinics above or use gettested.cdc.gov to find a site. If you have symptoms, tell the clinic when you call. Chlamydia is curable, and one test is a simple way to find out.

Chlamydia: Symptoms, Testing and Treatment in Chicago