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 passed through sex. It is also one of the easiest to treat once it is found. The hard part is that it often gives no signal at all.

This guide explains the symptoms of chlamydia, who should be tested and how often, how testing works, and what treatment looks like. It also covers partners, retesting, Colorado rules and the places in Denver where testing is free or low cost. The facts come from the CDC STI Treatment Guidelines (2021), the U.S. Preventive Services Task Force (USPSTF), and Colorado and Denver public health sources, each named where it is used.

Key takeaways

The CDC says most people with chlamydia have no symptoms, so a test is the only way to know your status.
Is chlamydia curable? Yes. The CDC says it is treated with antibiotics prescribed by a clinician.
The CDC recommends yearly screening for sexually active women under 25, and for older women and other groups with higher chances of exposure. A clinician can help you decide what fits your situation.
Testing uses a urine sample or a swab. It is quick and usually painless.
The CDC recommends retesting about three months after treatment, because repeat infection is common.
In Denver, you can get tested for free at community outreach events and at HeyDenver. The Denver Sexual Health Clinic charges on a sliding scale of $0 to $70 for uninsured or out-of-network patients.

What chlamydia is and why it matters in Denver
Symptoms of chlamydia
Who should be tested, and how often
How chlamydia testing works
Is chlamydia curable? Chlamydia treatment explained
Partners, retesting and Colorado rules
Where to get tested in Denver
Sources

What chlamydia is and why it matters in Denver

Chlamydia is caused by a bacterium called Chlamydia trachomatis. According to the CDC, it spreads through vaginal, anal or oral sex with a person who has it. It can also pass from a pregnant person to a baby during delivery.

Anyone who is sexually active 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 a common infection, and it is treatable.

How common is it in Colorado?

The CDC's 2023 STI Surveillance state ranking tables list Colorado at 435.1 chlamydia cases per 100,000 people, which is 25,571 reported cases. That placed Colorado 31st among states for that year.

Denver numbers are older. In April 2019, the Public Health Institute at Denver Health reported preliminary 2018 estimates of about 7,317 Denver residents with chlamydia. It said diagnoses had risen 24% over four years. These figures are several years old and are not directly comparable with the 2023 state numbers. They show a long-running pattern, not today's count. For current local figures, check with the health department.

Case counts reflect who gets tested as well as who has an infection. More testing finds more cases. That is one reason public health teams encourage regular screening.

Why finding it early matters

Chlamydia is easy to treat. Left untreated, it can cause harm over time, especially in people with a uterus. The CDC notes that untreated chlamydia can lead to pelvic inflammatory disease (PID), ectopic pregnancy, chronic pelvic pain and infertility. In people with a penis, it can sometimes cause painful swelling near the testicles. These outcomes are the reason screening exists. They are not the likely result for everyone, and early treatment lowers the chance of them.

Symptoms of chlamydia

The CDC states that most people with chlamydia have no symptoms. When symptoms do appear, they often show up one to several weeks after exposure, and they can be mild enough to miss.

Because symptoms are unreliable, they cannot tell you whether you have chlamydia. Only a test can. Other infections and everyday conditions can cause the same signs. A clinician can sort out the cause.

Possible symptoms in people with a vagina or cervix

The CDC lists these signs:

Unusual vaginal discharge
A burning feeling when urinating
Bleeding between periods or after sex
Pain in the lower belly or pelvis
Pain during sex

If the infection moves up into the uterus and fallopian tubes, it can cause PID. Pelvic pain, fever or pain during sex are worth bringing to a clinician promptly.

Possible symptoms in people with a penis

Discharge from the penis
A burning feeling when urinating
Pain or swelling in one or both testicles, which is less common

Possible symptoms in the rectum and throat

Chlamydia can infect the rectum after receptive anal sex. The CDC lists rectal pain, discharge and bleeding as possible signs. Many rectal infections cause nothing noticeable.

Chlamydia can also be found in the throat after oral sex. The CDC notes that throat infections usually cause no symptoms.

Eye infections

Chlamydia can cause redness, irritation or discharge in the eye if infected fluid reaches it. A newborn can develop an eye infection or pneumonia if exposed during delivery. This is one reason pregnant people are screened.

When to see a clinician sooner

Any of the symptoms above are a good reason to book a visit. So is learning that a partner has tested positive for any STI. A new partner, or a condom that broke or slipped, can also be a reason to ask about testing.

The Denver Sexual Health Clinic says that testing-only visits are limited to gonorrhea, chlamydia, syphilis, HIV and hepatitis C, and that people with symptoms need a provider visit. If you have symptoms, say so when you call so the clinic can book the right type of appointment.

Who should be tested, and how often

Because chlamydia is so often silent, screening means testing people who feel fine. Two sources shape the advice: the CDC and the USPSTF.

Sexually active women and others with a cervix

The USPSTF recommends screening for chlamydia in sexually active women aged 24 years or younger. It also recommends screening for older women who are at increased risk. The CDC STI Treatment Guidelines (2021) recommend yearly screening for sexually active women under 25. For women 25 and older, the CDC recommends yearly screening when there are risk factors. These include a new partner, more than one partner, a partner who has other partners, or a partner with an STI.

Transgender men and nonbinary people with a cervix, and anyone else with a cervix, can use these guidelines too. The CDC advises basing screening on the body parts a person has and the kinds of sex they have, not on gender label alone.

Men who have sex with men

The CDC recommends at least yearly chlamydia screening for gay, bisexual and other men who have sex with men. Testing should cover each place of sexual contact, which may include the urethra, rectum and throat. The CDC says that screening every three to six months may be appropriate for people at higher risk, for example those with multiple or anonymous partners. A clinician can help set a schedule that fits your life.

Transgender and gender-diverse people

The CDC guidelines advise that screening depends on a person's anatomy and sexual practices. A transgender woman who has receptive anal sex, for example, could be offered rectal testing. A clinician who is comfortable with gender-diverse care can help you work this out. You can say which body parts are involved in sex, and you do not have to use any particular words.

People who are pregnant

The CDC recommends chlamydia screening at the first prenatal visit for pregnant people under 25 and for older pregnant people at increased risk. It recommends a repeat test in the third trimester for those at higher risk. Treating chlamydia during pregnancy lowers the chance of passing it to a baby.

Men who have sex with women only

The USPSTF has found that there is not enough evidence to recommend routine screening for chlamydia in men who have sex only with women. The CDC does not recommend routine screening for these men either, but it advises testing based on a person's circumstances, such as symptoms or a partner's diagnosis. This does not mean testing is unneeded. It means the question is best answered with a clinician who knows your history.

Anyone with symptoms or a partner who tested positive

The guidance above is about screening people without symptoms. If you have symptoms, or a partner has told you they have chlamydia, a clinician can test you at any age and in any group.

Can minors get tested in Colorado?

Yes. Colorado law, C.R.S. 25-4-409, says that a health care provider consulted by a minor must, at the minor's request, do an exam for a sexually transmitted infection, treat if needed, and discuss or prescribe preventive measures. Parental consent is not required under the statute. The law is confidential, with an exception for child protection reporting. The statute sets no minimum age. For a minor 13 or younger, the provider may involve a parent or guardian. If you are a teen with questions, call a clinic and ask how they handle confidentiality.

How chlamydia testing works

The standard tests are called nucleic acid amplification tests, or NAATs. The CDC recommends NAATs because they are the most sensitive way to find chlamydia. They look for the genetic material of the bacterium in a sample.

What samples are used

Vaginal swab. The CDC lists this as the preferred sample for people with a vagina. Many clinics let you collect it yourself in a private room.
Urine. For people with a penis, a first-catch urine sample is the usual sample. That means the first part of the stream, not midstream. Many clinics ask you not to urinate for a short time beforehand, and they will tell you the right timing.
Rectal swab. A clinician may suggest this for people who have had receptive anal sex.
Throat swab. A clinician may suggest this for people who have had oral sex.

You do not need a pelvic exam or a physical exam for chlamydia screening. Samples are usually taken in a few minutes.

Timing after exposure

People often ask how soon after sex a test will be accurate. The CDC treatment guidelines do not give a single waiting number for chlamydia that applies to everyone. If you were exposed recently, tell the clinic. A clinician can explain whether to test now, test and repeat later, or start treatment in some cases based on your situation.

Getting results

Turnaround time depends on the clinic and its lab. Ask when you are tested how and when you will be told, and by what route, such as a call or a patient portal. If you do not hear back, call and ask. Do not assume that no news means a negative result.

What a result means

A positive NAAT result means the test found chlamydia. A negative result means the test did not find it in the sample taken at that time. A clinician can explain how a result fits with your recent exposures and symptoms. Tests are very good but no test is perfect, and results only describe the samples taken.

Test of cure

After treatment, the CDC does not recommend a routine repeat test right away for most non-pregnant people. The exception is pregnancy, where a clinician will advise a follow-up test. A test too soon after treatment can come back positive because of leftover bacterial material, which can be confusing. Retesting at about three months is a different matter, and it is covered below.

Privacy and reporting

Under Colorado's reporting rules (6 CCR 1009-1, Appendix A), laboratories and providers must report chlamydia, from any site, to public health within four days. Public health uses these reports to track trends and to help connect partners to care. Reports are handled under health privacy rules. A clinic can explain how your information is used.

Is chlamydia curable? Chlamydia treatment explained

Yes, chlamydia is curable. The CDC states that it can be cured with the right antibiotics. Treatment comes from a clinician, who will choose the medicine and tell you how to take it.

What chlamydia treatment involves

The CDC STI Treatment Guidelines (2021) recommend the antibiotic doxycycline as the first choice for most adults and adolescents. Other antibiotics, such as azithromycin, are listed as alternatives when doxycycline is not a good fit. In pregnancy, clinicians use a different choice, because doxycycline is generally avoided. Your clinician will pick the one that suits you based on your health, other medicines and pregnancy status. Do not use leftover antibiotics or a friend's prescription.

Take the medicine exactly as the clinician and pharmacist explain it. Finishing the whole course matters, even if symptoms ease sooner.

Do not have sex until your clinician says it is safe

The CDC advises people to avoid sex until treatment is finished and until their partners are treated, so that the infection does not pass back and forth. Your clinician will tell you how long to wait in your case.

Treatment in pregnancy

Pregnant people with chlamydia are treated with an antibiotic that a clinician judges safe in pregnancy. The CDC recommends a follow-up test after treatment in pregnancy. Prompt treatment lowers the chance of passing chlamydia to a baby.

If symptoms linger

Some symptoms take a few days to fade after treatment starts. If symptoms continue, return, or if you have pelvic pain, fever or testicular pain, contact a clinician. Persistent symptoms can come from reinfection by an untreated partner, from another infection, or from something unrelated. Only a clinician can sort that out.

Can you get chlamydia again?

Yes. Treatment cures the infection but does not give lasting protection. You can get chlamydia again if you have sex with someone who has it. The CDC notes that repeat infections are common, which is why it recommends retesting. Getting it again says nothing about you. It usually means a partner was not treated, or a new exposure happened.

Prevention options

The CDC lists condoms and dental dams as ways to lower the chance of chlamydia when used correctly each time. Regular testing and talking with partners about testing also help. In 2024, the CDC issued guidance on doxycycline taken after sex (doxy-PEP). It recommends that clinicians discuss doxy-PEP with gay, bisexual and other men who have sex with men, and with transgender women, who have had a bacterial STI in the past year. The CDC says doxy-PEP lowers chlamydia and syphilis, with a smaller effect on gonorrhea. It is a prescription decision with a clinician. The Denver Sexual Health Clinic's page does not state whether it offers doxy-PEP, so ask the clinic directly.

Partners, retesting and Colorado rules

Treating chlamydia works best when partners are treated at the same time. Otherwise, a partner can pass the infection back.

Telling partners

The CDC recommends that partners who had sex with a person in the 60 days before their symptoms started, or before their diagnosis, be tested and treated. If there was no partner in that window, the most recent partner should be evaluated. Telling a partner can feel hard. Plain, calm words work well: "I tested positive for chlamydia. It is treatable. I'd like you to get tested or treated too." Public health staff at the Denver Sexual Health Clinic can talk through options if you want help.

Expedited partner therapy in Colorado

Expedited partner therapy, or EPT, means a clinician gives a patient medicine or a prescription to pass to a partner without the partner being examined first. The CDC recommends EPT for heterosexual partners of people with chlamydia where the law allows it. For partners of men who have sex with men, the CDC says there is less information, and it advises that the partner be seen in person.

The CDC's page on the legal status of EPT in Colorado does not identify a Colorado statute written specifically for EPT. It cites a state pharmacy law requiring the patient's name on a prescription label as a negative factor. It also cites supportive policies from the Colorado Board of Medical Examiners (Policy 40-10) and the State Board of Pharmacy (Policy 40-4). The practical point is that EPT is not a clear-cut yes or no in Colorado. Ask your clinician whether they can offer it, and whether your partner should be seen in person instead.

Retesting at three months

The CDC recommends retesting about three months after treatment for chlamydia, for anyone treated, whether or not their partners were treated. This is not because treatment failed. It is because reinfection is common. If you cannot retest at three months, the CDC advises testing whenever you next see a clinician within the following 12 months.

Put a reminder in your phone on the day you are treated. Many people never go back for this test, and it is one of the simplest ways to protect your health.

Chlamydia and other infections

Chlamydia can occur alongside other infections, such as gonorrhea. The CDC advises that people diagnosed with one STI be offered testing for others, including HIV and syphilis. At the Denver Sexual Health Clinic, a testing-only visit covers gonorrhea, chlamydia, syphilis, HIV and hepatitis C.

Chlamydia and HIV prevention

A recent bacterial STI can be one reason a clinician suggests talking about HIV prevention. The Denver Sexual Health Clinic says it will meet with anyone who wants to start PrEP, and that people who are not eligible for its own PrEP program receive referrals to navigators. HeyDenver also offers PrEP navigation at 822 E 19th Ave, which you can reach at 303-962-2880. If you were exposed to HIV in the past 72 hours, the Denver Sexual Health Clinic says to call as soon as possible about PEP.

Where to get tested in Denver

Denver has several options that are free or based on your ability to pay. Details come from each organization's published information. Hours and walk-in days can change, so call before you go. The full guide to STD testing in Denver and what it costs compares more of these options side by side.

Denver Sexual Health Clinic

This clinic is run by the Public Health Institute at Denver Health (Denver Public Health).

Address: 660 N. Bannock St., Pavilion L, 2nd Floor, Denver, CO 80204
Phone: 303-602-3540
Hours: Monday to Friday, 8 a.m. to 5 p.m. The clinic is closed from 8 to 9 a.m. on the second Monday of each month.
Appointments: required for all clinic visits. It does not take walk-ins.
Cost: uninsured or out-of-network patients pay on a sliding fee scale of $0 to $70. The clinic says no one is denied care because of ability to pay.
Services: STD, HIV and hepatitis C testing, treatment, PrEP and PEP.

Testing-only visits are for gonorrhea, chlamydia, syphilis, HIV and hepatitis C. If you have symptoms, you will need a provider visit. This is also the place to go for treatment. See the Public Health Institute at Denver Health page on STD testing and treatment for current details.

Denver Health community outreach testing

Denver Health's community-based sexual health team offers free, confidential testing for STIs, HIV and hepatitis C at rotating locations around the Denver metro area. Testing is available in English and Spanish, and walk-ins are welcome. The team does not give physical exams or treatment. If you have symptoms or a known exposure, contact the Denver Sexual Health Clinic instead.

There is no single street address. Call or text 720-415-7075 for current locations. The published page does not list hours.

HeyDenver (Colorado Health Network)

HeyDenver is at 822 E 19th Ave, Denver, CO 80218. The phone number is 303-962-2880. Office hours are Monday to Friday, 9 a.m. to 4 p.m. HeyDenver's page lists testing for chlamydia and gonorrhea at three sites, rapid HIV tests, rapid syphilis tests, and hepatitis C testing case by case. Its Spanish-language page describes the STI testing as free, and its English page does not state a price.

Walk-in testing runs on set days, and other times are by appointment. Colorado Health Network's own testing page lists this site as testing by appointment, so confirm walk-in days before you go. Learn more at HeyDenver.

Planned Parenthood of the Rocky Mountains, Park Hill Health Center

This center is at 7155 E 38th Ave, Denver, CO 80207, phone (303) 321-2458. The CDC GetTested directory lists it as offering STD and HIV testing, accepting insurance and Medicaid, and not requiring an appointment. It says to contact the organization for eligibility. No prices or hours are published in that listing, so call to ask about fees and hours. See the CDC GetTested listing.

Clinica Tepeyac

Clinica Tepeyac is at 2101 E 48th Ave, Denver, CO 80216, phone (303) 458-5302. The CDC GetTested directory lists STD and HIV testing, a sliding scale, and acceptance of insurance and Medicaid. An appointment is required. Hours and prices are not published there, so call to confirm. See the CDC GetTested listing.

STRIDE Community Health Center, Oneida

STRIDE's Oneida location is at 2255 S Oneida St, Denver, CO 80224, phone 303-778-7433. It is open Monday to Friday, 7 a.m. to 5:30 p.m., and closed on weekends. STRIDE's women's health page lists STI testing and treatment, but the Oneida location page does not mention it. Call to confirm that testing is offered there, and ask about cost. See STRIDE Oneida.

Free mail-in testing for Colorado residents

Denver Public Health provides TestYourselfColorado.com. It offers free mail-in chlamydia and gonorrhea testing, and an at-home HIV test once a year, for Colorado residents 18 or older. It is not meant for people who are pregnant or have symptoms. More frequent testing every three months is available at low cost, and treatment is free. Ask the program how results and treatment work.

Finding more options

The CDC's GetTested directory lets you look up testing sites by ZIP code. Any listing there is a starting point. Call to confirm services, cost and hours.

What to ask when you call

Do you test for chlamydia at the throat and rectum as well as by urine or vaginal swab?
What will it cost for me, with or without insurance?
How and when will I get my results?
Can you treat me on site if the result is positive, or will you send a prescription?
Can my partner be treated, and how?
How is my information kept private?

Common questions

Can chlamydia go away on its own? The CDC recommends treatment for everyone who tests positive, because untreated infection can lead to lasting harm. Do not wait to see whether it resolves.

Does a negative result last forever? No. A test only describes the time it was taken. A new partner or exposure can mean a new test.

Will insurance bill my parents? This depends on the plan and the policyholder. Ask the clinic about confidentiality and billing before the visit. Colorado's minor consent law protects a minor's ability to get care without parental consent.

Is it okay to get tested if I feel fine? Yes. Most people with chlamydia feel fine, which is why screening exists.

The bottom line

Chlamydia is common, often silent and curable. If you are due for screening, have symptoms, or a partner has told you about a diagnosis, contact one of the Denver options above. A test is quick, and treatment from a clinician works. If the result is positive, you will have a plan for treating it, telling partners and retesting in about three months.

Chlamydia: Symptoms, Testing and Treatment in Denver