What are the symptoms of chlamydia?

What are the symptoms of chlamydia?
Chlamydia is a common sexually transmitted disease (STD) caused by infection with the obligate intracellular bacterium Chlamydia trachomatis. Chlamydia is transmitted through sexual contact with the penis, vagina, mouth, or anus of an infected individual. It can also be transmitted from a mother with an untreated chlamydial cervical infection to her newborn during childbirth (1). 

Most individuals infected with chlamydia remain asymptomatic, with only an estimated 10% of infected males showing symptoms and 5-30% of infected females (2).

Symptoms in females
C. trachomatis initially infects the cervix of females and sometimes the urethra, but at least 70% of infected females don’t notice any symptoms. For those that do experience symptoms, the most common signs are:

  • Dysuria – burning, tingling, or stinging when urinating
  • Mucopurulent endocervical discharge – abnormal vaginal discharge
  • Easily induced endocervical bleeding – bleeding between periods and/or after sexual intercourse
  • Increased urinary frequency
  • Pain during sexual intercourse
  • Abdominal and/or pelvic pain

Untreated chlamydial infections in females can lead to pelvic inflammatory disease (PID), and PID-associated infertility, ectopic pregnancy, and chronic pelvic pain. Untreated chlamydia during pregnancy has been associated with preterm delivery (3). Chlamydial infections can be passed to newborns during delivery, increasing the risk of conjunctivitis (18-44% of cases) and pneumonia (3-16% of cases) (4). 

Symptoms in males
In males, C. trachomatis can infect the urethra (tube through the penis) and, less commonly, the epididymis (tube at the back of the testicles). The majority of infected males do not show any symptoms. For those that do experience symptoms, the most common signs are:

  • Dysuria – burning, tingling, or stinging when urinating
  • Mucoid or watery urethral discharge from the penis
  • Burning or itching in the urethra
  • Irritation at the tip of the penis
  • Testicular pain, which may spread to the groin
  • Swollen, red, or warm scrotum
  • Abdominal and/or pelvic pain

Complications in untreated males are rare, but can include infertility.

Infections in the rectum
C. trachomatis can also affect the rectum in both males and females. This can occur through receptive anal sex or spread from the cervix and vagina in a female with a cervical chlamydial infection. The symptoms of an infection in rectum can include rectal pain, discharge, and bleeding (5).

Chlamydial conjunctivitis
Sexually acquired chlamydial conjunctivitis can occur in both males and females (6). Inflammation of the conjunctiva leads to:

  • Bloodshot eyes
  • Watery eyes, due to overactive tear glands
  • Mucus production that sticks to and coats the eyelashes
  • Eye pain and grittiness feeling
  • Swelling and redness of the eyes
  • Eye irritation and itchiness

1. Sexually Transmitted Disease Surveillance, 2018. CDC. October 2019. 
2. Farley TA, Cohen DA, Elkins W. (2003). Asymptomatic sexually transmitted diseases: the case for screening. Prev Med, 36 (4), 502-509.
3. Rours GI, et al. (2011). Chlamydia trachomatis infection during pregnancy associated with preterm delivery: a population-based prospective cohort study. Eur J Epidemiol, 26 (6), 493-502.
4. Frommell GT, et al. (1979). Chlamydial infection of mothers and their infants. J Pediatrics, 95 (1), 28-32.
5. Quinn TC, et al. (1981). Chlamydia trachomatis Proctitis. N Engl J Med, 305, 195-200.
6. Kalayoglu MV. (2002), Ocular chlamydial infections: pathogenesis and emerging treatment strategies. Curr Drug Targets Infect Disord, 2 (1), 85-91.