Chlamydia
Condition
Definition
Chlamydia is a common sexually transmitted infection (STI).
Causes
Bacteria from an infected sex partner causes the infection. This can happen during oral, genital, or anal sex.
Risk Factors
Chlamydia is most common in people under 24 years of age. Other things that may raise the risk are:
- Being sexually active
- Prior STIs
- Having a new sex partner
- Having more than one sex partner
- Having a partner with an STI
- Having sex without a condom
Symptoms
Most people do not have symptoms.
In men, symptoms may be:
- Pain when passing urine (pee)
- Pus exiting the penis
- Scrotal pain or swelling
In women, symptoms may be:
- A change in vaginal discharge
- Pain or bleeding during sex or between periods
- Belly pain
- Vaginal redness or pain
- Pain when passing urine
Copyright © 2002 Nucleus Communications, Inc. All rights reserved.

Copyright © 2002 Nucleus Communications, Inc. All rights reserved.

Diagnosis
The doctor will ask about symptoms and past health. A physical exam will be done. Tests for cause of the infection may be done with:
- A swab of the penis, cervix, throat, or rectum
- Urine tests
Treatment
Antibiotics are used to treat the infection. Sexual partners should also be treated or the infection will continue to recur.
Prevention
The risk of chlamydia may be lowered by:
- Abstaining from oral, anal, or genital sex.
- Limiting sex to one partner
- Using latex condoms during sex
Centers for Disease Control and Prevention
Office on Women's Health—US Department of Health and Human Services
CANADIAN RESOURCES:
Health Canada
The Sex Information & Education Council of Canada
Centers for Disease Control and Prevention
Office on Women's Health—US Department of Health and Human Services
CANADIAN RESOURCES:
Health Canada
The Sex Information & Education Council of Canada
References
- Chlamydia. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/std/chlamydia/default.htm.
- Chlamydia fact sheet. Office on Women's Health—US Department of Health and Human Services website. Available at: http://www.womenshealth.gov/publications/our-publications/fact-sheet/chlamydia.html.
- Chlamydia genital infection. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/chlamydia-genital-infection.
- Sexually transmitted infections treatment guidelines, 2021. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/std/treatment-guidelines/default.htm.
Contributors
- Beverly Siegal, MD, FACOG
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