Chlamydia: The Most Common STI

If you're 24 or younger and sexually active, you are at high risk for getting chlamydia. Chlamydia is the most common sexually transmitted infection (STI) in the country. It is caused by bacteria that infect the cells of the cervix in women and the urethra in men. It is spread during vaginal, oral, or anal sex with someone who is infected.

Regular testing is important, because you usually won't have symptoms. If caught early, chlamydia is easily treated with antibiotics. If left untreated, if can lead to pelvic inflammatory disease, infertility (inability to get pregnant), or permanent damage to the fallopian tubes. This increases the risk for an ectopic pregnancy (a pregnancy in the fallopian tube) if you get pregnant. It can also cause serious infections in infants born to infected mothers.

How Is It Diagnosed?

Because chlamydia is often a "silent" disease with no symptoms, getting regular chlamydia tests is the only way to find the infection. A lab test is done either from a self-swab test, a urine sample, or a Pap smear.

Who Should Be Tested?

If you're sexually active, not pregnant, and 24 or younger, get tested every year. An annual exam is also recommended if you are over 24 years old and at increased risk (see below).

If you're pregnant and 24 or younger, get tested during your first prenatal visit. If you have a new sexual partner during the pregnancy, a second test should be done at the third trimester. If you're pregnant and over 24, get tested if you are at increased risk for chlamydia.

You should also be tested if you have a new sexual partner or don't always use a condom when you have sex.

How Can I Get Tested?

Contact your doctor and ask for a chlamydia test. If you don't have symptoms, you will only need to leave a urine sample. If you have symptoms — such as pain in your abdomen or genitals, discharge, or urinary symptoms — you will need an exam.

If you are aged 14 or older, testing is confidential. Information isn't given to anyone but you. If you are aged 13 or younger, information may be shared with your parents.

What Is the Treatment?

Antibiotics are usually prescribed to treat chlamydia. If you have chlamydia, you need to tell your sexual partner. He or she will need to be treated as well. You and your partner should be treated at the same time to avoid passing the infection back and forth to one another.

What Increases My Risk for Chlamydia?

The following increases your risk for getting an STI, including chlamydia:

How Can I Lower My Risk?

If you have sex, use a condom or latex barrier every time to protect yourself from STIs. Avoid high-risk sexual behaviors. Talk openly with your partner about what you can both do to lower your risk of getting an STI. The only sure way to prevent getting chlamydia is by not having vaginal, oral, or anal sex.

For More Information

If you're a Group Health member and have a medical question or concern, call the Consulting Nurse Service.

In Eastern Washington, Central Washington, and North Idaho: During office hours, call the medical center where you receive care. After hours, call the Consulting Nurse Service.


Clinical review by Jeff Lindenbaum, MD
Group Health
Reviewed 05/15/2013