Understanding Chlamydia: A Comprehensive Guide
Evidence-based information about chlamydia infection, symptoms, testing, treatment, and prevention.
Medically reviewed by healthcare professionals
Last updated: April 2025
What Is Chlamydia?
Chlamydia is one of the most common sexually transmitted infections (STIs) worldwide. It's caused by the bacterium Chlamydia trachomatis and can infect both men and women. Chlamydia often presents with no symptoms, earning it the nickname "the silent infection," which makes regular testing crucial for sexually active individuals.
The infection primarily affects the genital tract but can also infect the rectum, throat, and eyes. If left untreated, chlamydia can lead to serious health complications, especially in women, including pelvic inflammatory disease (PID) and infertility.
Quick Facts About Chlamydia
- Most common bacterial STI in the United States
- Approximately 75% of infected women and 50% of infected men show no symptoms
- Easily curable with antibiotics
- Can lead to serious complications if left untreated
- Regular testing is recommended for sexually active individuals, particularly those under 25
How Chlamydia Spreads
Chlamydia is transmitted through sexual contact with an infected person. This includes:
- Vaginal intercourse
- Anal intercourse
- Oral sex
- Sharing sex toys without washing them between uses or covering with a new condom
Chlamydia can also be passed from an infected mother to her baby during childbirth, potentially causing eye infections or pneumonia in newborns.
Important to Know
You cannot get chlamydia from casual contact such as hugging, sharing food, using the same toilet, or swimming in the same pool as someone who has the infection.
Sources & References
1. Centers for Disease Control and Prevention. (2022). Chlamydia - CDC Fact Sheet.
2. World Health Organization. (2022). Sexually transmitted infections (STIs): Chlamydia.
3. American College of Obstetricians and Gynecologists. (2021). Chlamydia, Gonorrhea, and Syphilis.
4. National Health Service UK. (2022). Chlamydia.
5. Mayo Clinic. (2022). Chlamydia trachomatis.