Chlamydia (kluh-MID-e-uh) is a common sexually transmitted disease.
Sexually transmitted diseases are infections spread mainly by contact with genitals or bodily fluids. Also called STDs, STIs or venereal disease, sexually transmitted infections are caused by bacteria, viruses or parasites.
Chlamydia is caused by Chlamydia trachomatis (truh-KOH-muh-tis) bacteria and spread through oral, vaginal or anal sex.
You might not know you have chlamydia because many people don't have symptoms, such as genital pain and discharge from the vagina or penis. Chlamydia trachomatis affects mostly young women, but it can occur in both men and women and in all age groups.
It's not difficult to treat, but if left untreated it can lead to more-serious health problems.
Early-stage Chlamydia trachomatis infections often cause few symptoms. Even when symptoms occur, they're often mild. That makes them easy to overlook, which is why regular screening is important.
Symptoms of Chlamydia trachomatis infection can include:
Depending on a person's sexual activity, Chlamydia trachomatis can infect the eyes, throat or rectum.
Eye infections, called conjunctivitis, cause the inside of the eyelid to be red and irritated. In the throat, an infection may have no symptoms, or a person may have a sore throat. An infection in the rectum may have no symptoms or may cause rectal pain, discharge or bleeding.
See your healthcare professional if you have a discharge from your vagina, penis or rectum, or if you have pain during urination. Also, see your healthcare team if you learn your sexual partner has chlamydia. Your healthcare professional will likely prescribe an antibiotic even if you have no symptoms.
The Chlamydia trachomatis bacterium is most commonly spread through vaginal, oral and anal sex. It also is possible for the bacterium to spread in pregnancy, during delivery of the baby. Chlamydia can cause pneumonia or a serious eye infection in the newborn.
People who have sex before age 25 are at higher risk of chlamydia than are older people. That's because younger people are more likely to have more than one risk factor.
Risk factors for chlamydia include:
Chlamydia trachomatis can be associated with:
The surest way to prevent chlamydia infection is to abstain from sexual activities. Short of that, you can:
A medicine called doxycycline may be an option to prevent infection among people at higher risk than average of getting chlamydia. Higher risk groups include men who have sex with men and transgender women.
Taking doxycycline within 3 days of sexual activity lowers the risk of an infection with the bacteria that cause chlamydia. Your healthcare professional can prescribe doxycycline and any testing you need while taking the medicine.
The Centers for Disease Control and Prevention recommends chlamydia testing for anyone with chlamydia symptoms. Regardless of symptoms, talk to your healthcare team to find out how often you should be screened for chlamydia. In general, some groups are screened more often than others, such as:
Screening and diagnosis of chlamydia is relatively simple. You may be able to use a test that's available without a prescription, sometimes called an at-home test, to see if you have chlamydia. If that test shows you have chlamydia, you'll need to see a healthcare professional to confirm the diagnosis and start treatment.
To determine whether you have chlamydia, your healthcare professional will analyze a sample of cells. Samples can be collected with:
Chlamydia trachomatis is treated with antibiotics. You will likely need to take a medicine for seven days, or you may be given a one-time dose of a medicine.
In most cases, the infection clears up within 1 to 2 weeks after you take the antibiotic. But you can still spread the infection at first. So avoid sexual activity from when you start treatment until all your symptoms are gone.
Your sexual partner or partners from the last 60 days also need screening and treatment even if they don't have symptoms. Otherwise, the infection can be passed back and forth between sexual partners. Make sure to avoid sexual contact until all exposed partners are treated.
Having chlamydia or having been treated for it in the past doesn't prevent you from getting it again.
Three months after treatment, the Centers for Disease Control and Prevention recommends getting tested for chlamydia again. This is to make sure people haven't been reinfected with the bacteria, which can happen if sex partners aren't treated, or new sex partners have the bacteria.
If you think you have a sexually transmitted infection, such as Chlamydia trachomatis, see a healthcare professional.
Before your appointment, prepare to answer the following questions:
You also might want to prepare a list of questions to ask your healthcare professional. Sample questions include:
Your healthcare professional is likely to ask you a number of questions, such as: