Chlamydia is a common sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis.

People mainly transmit chlamydia through unprotected vaginal, anal or oral sex. A pregnant person can also pass the infection to their baby during childbirth.

Importantly, many people with chlamydia have no symptoms. As a result, they may pass the infection to others without knowing it.

Fortunately, doctors can usually treat chlamydia effectively with antibiotics. However, untreated infection can lead to serious complications, so testing and early treatment are important.

What Are the Symptoms of Chlamydia?

Many people with chlamydia have no symptoms.

However, when symptoms do occur, they can vary depending on which part of the body is affected.

Symptoms in Women

Possible symptoms include:

• unusual vaginal discharge
• pain or burning when urinating
• bleeding between periods
• bleeding after sex
• pain during sex
• lower abdominal or pelvic pain

Because symptoms can be mild or absent, regular sexual health testing can be important for people at increased risk.

Symptoms in Men

Possible symptoms include:

• discharge from the penis
• pain or burning when urinating
• irritation or redness around the opening of the penis
• pain or swelling in one or both testicles

Rectal Symptoms

Chlamydia can also affect the rectum.

Symptoms may include:

• rectal pain
• discharge
• bleeding

However, rectal infection may also occur without symptoms.

Throat Infection

Chlamydia can sometimes infect the throat after oral sex.

Most throat infections do not cause noticeable symptoms.

How Is Chlamydia Spread?

People mainly transmit chlamydia through sexual contact with someone who has the infection.

Transmission can occur through:

• vaginal sex
• anal sex
• oral sex
• sharing sex toys without cleaning them or using a new condom

A pregnant person can also pass the infection to their baby during childbirth.

Chlamydia is not usually spread through everyday contact such as hugging, sharing food, toilet seats or swimming pools.

Who Should Consider Chlamydia Testing?

Your doctor may recommend testing if you:

• have symptoms of an STI
• have had unprotected sex with a new or casual partner
• have recently changed sexual partners
• have a partner who has been diagnosed with chlamydia
• have another STI
• need routine sexual health screening
• are pregnant and your healthcare professional recommends testing

Because chlamydia often causes no symptoms, testing can identify infections that would otherwise go unnoticed.

How Is Chlamydia Diagnosed?

Testing is usually simple.

Depending on your circumstances, your healthcare professional may use:

• a urine sample
• a vaginal swab
• a cervical swab
• a rectal swab
• a throat swab

In some cases, you can collect the swab yourself.

Your doctor or sexual health clinic will recommend the most appropriate test based on your symptoms and sexual history.

You can find more information about STI testing from Healthdirect.

Treatment for Chlamydia

Doctors treat chlamydia with antibiotics.

The exact antibiotic and length of treatment depend on factors such as:

• the location of the infection
• pregnancy
• allergies
• whether complications are present
• current Australian treatment guidelines

Take the medicine exactly as prescribed and complete the full course if your treatment requires more than one dose.

Do not share antibiotics with another person.

When Can You Have Sex Again?

Your doctor will tell you how long to avoid sexual contact after treatment.

In general, avoid vaginal, anal and oral sex until the recommended period after treatment has passed and current sexual partners have also received appropriate testing and treatment.

This helps reduce the chance of passing the infection back and forth.

Do Sexual Partners Need Treatment?

Yes.

Recent sexual partners may need testing and treatment, even if they do not have symptoms.

Because many people do not realise they have chlamydia, partner notification is an important part of treatment.

Your doctor or sexual health service can advise which partners you should contact and may help with confidential partner notification.

Can You Get Chlamydia More Than Once?

Yes.

Importantly, having chlamydia once does not provide immunity, so you can become infected again.

Reinfection is common when sexual partners have not received testing or treatment.

Therefore, your healthcare professional may recommend repeat testing after treatment.

What Happens if Chlamydia Is Not Treated?

Without treatment, chlamydia can lead to several complications.

Complications in Women

The infection can spread to the uterus and fallopian tubes and cause pelvic inflammatory disease (PID).

Possible complications include:

• chronic pelvic pain
• damage to the fallopian tubes
• infertility
• increased risk of ectopic pregnancy

Complications in Men

Possible complications include:

• inflammation around the testicles
• testicular pain and swelling
• fertility problems in some cases

Other Complications

Chlamydia can occasionally contribute to:

• inflammation of the rectum
• reactive arthritis
• eye infection

Therefore, early diagnosis and treatment can reduce the risk of these complications.

Chlamydia During Pregnancy

If you have chlamydia during pregnancy, your doctor should supervise your treatment.

Untreated infection may increase the risk of pregnancy complications and can pass to the baby during birth.

Newborn infection may cause problems such as conjunctivitis or pneumonia.

If you are pregnant or planning a pregnancy and think you may have been exposed to an STI, speak with your doctor or maternity healthcare professional.

Chlamydia and Other STIs

Having one sexually transmitted infection does not protect against others.

Depending on your circumstances, your healthcare professional may recommend testing for other infections such as:

• gonorrhoea
• syphilis
• HIV
• hepatitis B

You may also find our Herpes guide useful for information about another common sexually transmitted infection.

How to Reduce Your Risk

There is no guaranteed way to prevent chlamydia other than avoiding sexual contact, but you can reduce the risk.

Helpful measures include:

• using condoms correctly during vaginal and anal sex
• using condoms or dental dams during oral sex
• using a new condom when sharing sex toys
• having regular STI testing when appropriate
• discussing STI testing with new partners
• avoiding sexual contact until treatment has been completed when an STI is diagnosed

In addition, using condoms correctly can significantly reduce the risk of many STIs.

When Should You See a Doctor?

Arrange a sexual health check if:

• you have symptoms that may be caused by chlamydia
• a sexual partner has been diagnosed with chlamydia
• you have had unprotected sex and are concerned about STI exposure
• you have a new or casual sexual partner and would like routine testing
• symptoms continue after treatment

You should also seek medical advice if you develop pelvic pain, testicular pain or unusual genital discharge.

When Is Urgent Medical Assessment Needed?

Seek prompt medical care if you experience:

• severe lower abdominal or pelvic pain
• significant testicular pain or swelling
• fever with pelvic pain
• fainting or severe dizziness
• severe abdominal pain during pregnancy
• heavy or unusual vaginal bleeding with significant pain

These symptoms may indicate a complication that needs further assessment.

Sexual Health Testing

Healthcare services provide confidential and straightforward STI testing.

Depending on your location, testing may be available through:

• your GP
• sexual health clinics
• family planning services
• community health services

For more information about sexual health services, see Healthdirect.

Speak With Your Pharmacist

Your MediAdvice pharmacist can provide general information about medicines and antibiotic use.

However, suspected chlamydia requires appropriate testing and medical assessment. Therefore, your pharmacist may recommend that you see your GP or attend a sexual health clinic.

If your doctor prescribes antibiotics, your pharmacist can explain how to take them correctly, discuss possible side effects and check for medicine interactions.

General advice only: This information is not intended to replace advice from your healthcare professional. If you think you may have chlamydia or another sexually transmitted infection, arrange appropriate testing and medical advice.