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Chlamydia Infection

Written by Ada’s Medical Knowledge Team

Updated on

What is genital tract chlamydia infection?

Chlamydia is a common sexually transmitted disease and most commonly affects men and women between the ages of 15 and 24.[1][2] It is a bacterial infection caused by Chlamydia trachomatis and can be passed on through unprotected sexual intercourse (sex without a condom).[3]

Chlamydia symptoms may not be noticed by infected individuals, however, symptoms can develop which include lower abdominal pain, pain when urinating, and a vaginal discharge in women or discharge from the penis in men.[2][3]

The diagnosis can be made with a urine test or a swab of the genitals. Antibiotics are used to treat Chlamydia infections, and most people recover well after treatment. However, untreated chlamydia can spread and cause potentially serious complications.[3]

People concerned that they may be experiencing chlamydia symptoms can also use the free Ada app to carry out a symptom assessment or find out more about the symptom checker first.

Risks for chlamydia infection

Sexually active people can become infected by having unprotected vaginal, anal or oral sex with a partner who has already been infected.[2] Risk factors for contracting a Chlamydia infection can include:[3][4]

  • Being under 25 years years old and sexually active
  • Having a new sexual partner or multiple sexual partners
  • Having sex with an infected partner
  • Not using condoms
  • History of a prior sexually transmitted infection

The risk of infection is greatest in those who are under 25 years of age, particularly female adolescents and men who have sex with men.[5] Additionally, patients who have had a prior STI (sexually transmitted infection) should be routinely assessed for re-exposure. An individual with a prior chlamydial infection has a high risk of re-infection and should be assessed 3-months after treatment is complete.[5]

Chlamydia symptoms

Approximately 85% of men and women do not show any symptoms of a Chlamydia infection.[6] Chlamydia symptoms for women can include menstrual bleeding, postcoital bleeding (vaginal bleeding after sex), odourless vaginal discharge, painful urination or pelvic pain.[6] Chlamydia infection can move up the urogenital tract and cause:[6]

  • Fever
  • Chills
  • Muscle pain
  • Nausea
  • Vomiting
  • Pelvic or abdominal pain

Chlamydia symptoms for men include painful urination (dysuria) and white, cloudy or watery discharge from the penis. Other symptoms in men can include:[6][7]

  • Burning or itching in the urethra (the tube that carries urine outside of the body)
  • Mild to severe scrotal pain; the scrotum is the pouch which contains and protects testicles.

Diagnosing a chlamydia infection

Chlamydia infection can be diagnosed based on symptoms, physical examination and laboratory investigations.[6] A doctor may perform a physical examination and may request collection of a urine sample or swab sample of the affected genital area, this can be collected by a physician, however, self-collection is also possible.[6][8][9]

The collected urine or swab sample is used in the ‘Nucleic-acid amplification test’ (NAAT) which is the currently recommended laboratory test to diagnose Chlamydia.[6][8] A positive NAAT test can confirm the presence of Chlamydia and treatment should be started.

Chlamydia treatment

Effective treatment of Chlamydia is by taking antibiotic tablets. With the correct use of antibiotics, Chlamydia infection can be cured.[10] Antibiotics that are used for Chlamydia treatment can be:[10]

  • Doxycycline
  • Azithromycin

It is important to tell all sexual partners from the past 2 months, and partners who may have been exposed to Chlamydia about the diagnosis so that they can also get tested and treated.[10]

People who are being treated for chlamydia with Doxycycline should not have sex until the antibiotic treatment is finished.[10] Those who are treated with Azithromycin are advised to wait 7 days after treatment before sexual intercourse.[10]

Complications

Complications may arise from chlamydia. In women, possible complications include:[11][12]

  • Pelvic inflammatory disease (PID): can lead to infertility, chronic pelvic pain and increased risk of ectopic pregnancy (where a fertilised egg is implanted outside the womb). The risk is low with appropriate antibiotic treatment
  • Pregnancy complications: chlamydia infection that is not treated during pregnancy increases risk of your baby to contract an eye infection (conjunctivitis) or lung infection (pneumoniae).
  • Premature labor and birth [12]

Complications in men include inflammation of the testicles and reactive arthritis.

Prevention

Practising safe sex is the main way to prevent a chlamydia infection. Making sure that sexual partners get tested and treated also helps to prevent the spreading of the infection.

Chlamydia FAQs

What does chlamydia look like?

Chlamydia infection does not have a specific appearance, it presents with odorless vaginal discharge, menstrual bleeding or postcoital bleeding and painful urination or pelvic pain.

Is chlamydia curable?

Yes, with appropriate antibiotic treatment, Chlamydia infections can be cured.

Can you get chlamydia from kissing?

No, chlamydia infections cannot be transmitted through casual contact such as kissing, hugging or holding hands.

Are bumps on the tongue a sign of chlamydia in the throat?

Chlamydia infection in the throat can occur from oral sex and mostly does not show any symptoms. Symptoms can include mouth pain, mouth sores, and sore throat. Bumps on the tongue can occur but are very rare.

Does chlamydia cause bumps on the inner thigh?

A different type of chlamydia trachomatis infection can cause an STI known as ‘Lymphogranuloma Venereum’. This can cause blisters that heal quickly, followed by painful, tender swelling in the groin.

What causes chlamydia?

Chlamydia is a common sexually transmitted disease (STD). It is a bacterial infection caused by Chlamydia trachomatis.

How do you get chlamydia?

Chlamydia is transmitted by unprotected sexual intercourse (oral, vaginal or anal sex).

How long does chlamydia last?

Chlamydia infection lasts approximately 1 week with effective antibiotic treatment.

How to treat chlamydia?

Chlamydia is treated with antibiotics. The most commonly used antibiotics are Doxycycline or Azithromycin.

What are chlamydia symptoms in men?

Chlamydia symptoms in men include painful urination (known as dysuria) and white, cloudy or watery discharge from the penis. Burning or itching in the urethra (where urine leaves the body) and scrotum pain are also possible.

What are chlamydia symptoms in women?

Chlamydia symptoms for women can include menstrual bleeding, vaginal bleeding after sex, odourless vaginal discharge, painful urination or pelvic pain. It is also possible to experience fever, chills, muscle pain, nausea, vomiting and abdominal pain which can indicate an ascending infection of the genital tract.


  1. Kreisel KM, et al. (2021). Sexually Transmitted Infections Among US Women and Men: Prevalence and Incidence Estimates, 2018. Accessed 17 May, 2022.

  2. CDC (2022). Chlamydia - CDC Fact Sheet (Detailed). Accessed 17 May, 2022.

  3. NHS(2021). Chlamydia, Overview. Accessed 17 May, 2022.

  4. BMJ Best Practice (2022). Genital tract chlamydial infection, history and exam, risk factors.. Accessed 17 May, 2022.

  5. Workowski KA, et al. (2021). Sexually Transmitted Infections Treatment Guidelines, 2021. Accessed 17 May, 2022.

  6. BMJ Best Practice (2022). Genital tract chlamydial infection, Approach. Accessed 17 May, 2022.

  7. NHS (2021). Chlamydia, Symptoms. Accessed 17 May, 2022.

  8. Workowski KA, et al. (2021). Sexually Transmitted Infections Treatment Guidelines, 2021. Accessed 17 May, 2022.

  9. NHS (2021). Chlamydia, Diagnosis. Accessed 17 May, 2022.

  10. NHS (2021). Chlamydia, Treatment. Accessed 17 May, 2022.

  11. BMJ Best Practice (2022). Genital tract chlamydial infection, Complications. Accessed 17 May, 2022.

  12. NHS (2021). Chlamydia, Complications. Accessed 17 May, 2022.

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