Definition

Chlamydia is an infection caused by the bacteria Chlamydia trachomatis. It is most often spread through sexual contact.

Causes

Both males and females may have chlamydia. However, they may not have 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
• Have been infected with chlamydia before

Symptoms

In men, chlamydia may cause symptoms similar to gonorrhea. Symptoms may include:

• Burning feeling during urination
• Discharge from the penis or rectum
• Tenderness or pain in the testicles
• Rectal discharge or pain

Symptoms that may occur in women include:

• Burning feeling during urination
• Painful sexual intercourse
• Rectal pain or discharge
• Symptoms of pelvic inflammatory disease (PID), salpingitis (inflammation of the fallopian tubes), or liver inflammation similar to hepatitis
• Vaginal discharge or bleeding after intercourse

Exams and Tests

If you have symptoms of a chlamydia infection, your health care provider will collect a sample for culture or a test called a nucleic acid amplification.

In the past, testing required an exam by a provider. Today, very accurate tests can be done on urine samples or vaginal swabs. Results take 1 to 2 days to come back. Your provider may also check if you have other types of sexually transmitted infections (STIs). Common STIs are:

• Gonorrhea
• HIV
• Syphilis
• Hepatitis
• Herpes

Even if you have no symptoms, you may need a chlamydia test if you:

• Are 24 years old or younger and sexually active (get tested every year)
• Are any age and have an increased risk for chlamydia infection such as having a new sexual partner, more than one partner or a partner with an STI

Treatment

The most common treatment for chlamydia is an antibiotic.

Both you and your sexual partners must be treated. This will ensure that you do not pass the infection back and forth. A person may become infected with chlamydia many times.

You and your partner are asked to abstain from sexual intercourse during the time of treatment.

A follow-up may be done in 4 weeks to see if the infection has been cured.

Outlook (Prognosis)

Antibiotic treatment almost always works. You and your partner should take the medicines as directed.

If chlamydia spreads into your uterus and fallopian tubes, it can cause scarring. Scarring can make it harder for you to get pregnant.

You can help prevent infection with chlamydia by:

• Finishing your antibiotics when you are treated
• Making sure your sexual partners also take antibiotics
• Talking to your provider about being tested for chlamydia
• Going to see your provider if you have symptoms
• Wearing condoms and practicing safer sex

When to Contact a Medical Professional

Contact your provider if you have symptoms of chlamydia.

Many people with chlamydia may not have symptoms. Therefore, many sexually active adults should be screened for the infection yearly. Check with your provider about what is best for you.

References

Centers for Disease Control and Prevention website. Getting tested for STIs. www.cdc.gov/sti/testing/. Updated April 9, 2024. Accessed July 24, 2024.

Centers for Disease Control and Prevention website. Sexually transmitted infections treatment guidelines, 2021. Chlamydial infections in adolescents and adults. www.cdc.gov/std/treatment-guidelines/chlamydia.htm. Updated July 22, 2021. Accessed April 22, 2024.

Reno HEL, Geisler WM. Diseases caused by chlamydiae. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 294.

US Preventive Services Task Force; Davidson KW, Barry MJ, et al. Screening for chlamydia and gonorrhea: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;326(10):949-956. PMID: 34519796 pubmed.ncbi.nlm.nih.gov/34519796/.