What is Chlamydia?

Chlamydia infection is a common sexually transmitted disease caused by the bacteria Chlamydia trachomatis, a strain of bacteria from the Chlamydiaceae family that usually affects the urogenital tract.


When an infected person has unprotected vaginal, oral or anal sex, the bacteria can be passed onto an uninfected partner. The bacteria can also pass from an infected mother to her unborn baby during delivery.

Symptoms of Chlamydia infection

Nearly 70 to 80% of women who develop chlamydia infection are unaware they are infected due to the absence of symptoms. Chlamydia can cause the cervix to become inflamed and infected women may complain of pain, bleeding and discharged pus while urinating or after sexual intercourse.

The infection can also pass into the upper genital tract and cause inflammation of the pelvic structures such as the womb, fallopian tubes and ovaries. This is called pelvic inflammatory disease.

Nearly 50% of men with chlamydia also do not have any symptoms. The symptom-free aspect to chlamydia means the infection can easily and unknowingly be spread to uninfected individuals and that the condition often goes undiagnosed while people continue to engage in sexual intercourse.

In men, chlamydia commonly causes urethritis or infection of the urethra. The urethra in males passes through the penis and lets out urine from the bladder. Therefore, among men, chlamydia may lead to pain on urination, difficulty in urinating and discharge of a whitish discharge from the tip of the penis. If the infection moves up the genital tract, and involves the vas deferens and testicle, epididymitis may develop in some affected males.

Over time, the complications of chlamydia may lead to infertility in both men and women.

Chlamydia infection may also affect the eyes as it leads to a condition called trachoma, one of the leading causes of blindness worldwide.

Diagnosis and treatment

Chlamydia infection is tested routinely in sexual health clinics as it is one of the most common sexually transmitted infections. Urine and genital swabs are taken and checked for presence of the bacteria. Tests can also be performed at home using home kits. Chlamydia is easily treated with appropriate antibiotics. Lack of timely treatment however may have serious long-term complications.

Further Reading

Last Updated: Feb 26, 2019

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.


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