Chlamydia is a sexually transmitted infection (STI). This means chlamydia is passed from one person to another during sexual contact.
Causes, incidence, and risk factors
Chlamydia is caused by the bacteria Chlamydia trachomatis. Both males and females may have chlamydia without having any symptoms. As a result, you may become infected or pass the infection to your partner without knowing it.
You are more likely to become infected with chlamydia if you:
Have sex without wearing a male or female condom
Have more than one sexual partner
Use drugs or alcohol and then have sex
Only some women with chlamydia have symptoms. Symptoms may include:
If you have symptoms of a chlamydia infection, your health care provider will collect a culture or perform a test called a PCR:
The culture will be collected during a pelvic exam.
Results will take 1 - 2 days to come back.
Your health care provider may also check you for other types of infections, such as gonorrhea.
Even if you have no symptoms, you may need a chlamydia test if you:
Are 25 years old or younger and are sexually active (get tested every year)
Have a new sexual partner or more than one partner
Chlamydia can be treated with the antibiotics azithromycin, tetracyclines, quinolones, or erythromycin. Erythromycin and azithromycin are safe if you are pregnant. You and your partner should finish all of your antibiotics, even if you feel better. Common side effects of these antibiotics include nausea, upset stomach, and diarrhea.
All of your sexual partners must be treated, even if they do not have symptoms. This will prevent you from passing the infection back and forth.
Because gonorrhea often occurs with chlamydia, treatment for gonorrhea is often given at the same time.
Antibiotic treatment almost always works if you and your partner take the medicines as directed.
If chlamydia spreads into your uterus, it can cause scarring and make it harder for you to get pregnant. You can help prevent this by:
Finishing your antibiotics when you are treated
Talking to your health care provider about being tested for chlamydia
Going to see your health care provider whenever you have symptoms
U.S. Preventive Services Task Force. Screening for chlamydial infection: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2007;147:128-134.
Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines. 2010. MMWR. 2010;59(RR-12):1-110.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington; and Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.