Chlamydia overview

Overview

Chlamydia is a common sexually transmitted infection (STI) caused by bacteria. It can infect the genitals, rectum, throat, and eyes. Many people with chlamydia do not have any symptoms, so they may not know they have it. Without treatment, it can cause serious health problems, but it is easily cured with antibiotics.

Yes, chlamydia is very common, especially among sexually active young people under 25. It is one of the most frequently reported STIs in the UK and worldwide.

Chlamydia affects anyone who is sexually active, including men, women, and people with vulvas or penises. It is most common in people aged 15–24, but it can affect people of any age. Having multiple sexual partners or not using condoms increases the risk.

Symptoms

Common symptoms

• No symptoms at all (most common)
• Pain or burning when urinating
• Unusual discharge from the penis or vagina
• Pain in the lower belly (abdomen)
• Pain during sex
• Bleeding between periods or after sex
• Pain or swelling in the testicles

Symptoms in children

• Chlamydia in children is rare and usually linked to sexual abuse. Symptoms may be similar to adults: discharge, pain when urinating, or itching around the genitals. Any suspicion should be discussed with a healthcare provider.

Symptoms in older adults

• Symptoms in older adults are similar to younger adults. Many have no symptoms. If symptoms occur, they may include discharge, pain when urinating, or pelvic discomfort.

Causes

Main causes

• Chlamydia is caused by bacteria called Chlamydia trachomatis. It spreads through unprotected vaginal, anal, or oral sex with an infected person. It can also be passed from a pregnant person to their baby during childbirth.

Risk factors

• Being sexually active (especially if under 25)
• Having multiple sexual partners
• Not using condoms consistently
• Having a previous STI
• Having a partner who has chlamydia or other STIs

When to see a doctor

See a doctor urgently if:

• If you have any symptoms of chlamydia, such as discharge or pain when urinating
• If you know you have been exposed to chlamydia (even without symptoms)
• If you have had unprotected sex with a new partner and are worried

Book a routine appointment if:

• All sexually active people under 25 should be tested for chlamydia yearly or when changing partners.
• Anyone who has never been tested for STIs should consider a routine check-up.

Diagnosis

A doctor or nurse will ask about your symptoms and sexual history. They will take a sample for testing. This is usually a urine sample or a swab from the vagina, penis, rectum, or throat.

Tests that may be done

• Urine test – you provide a sample of urine
• Swab test – a cotton bud is gently wiped over the area that might be infected
• Sometimes a blood test if other STIs are suspected

What to expect at your appointment

The test is quick and should not be painful. For a urine test, you may be asked not to pee for one to two hours beforehand. Results usually take a few days to a week. In the meantime, avoid sex until you get the all-clear. Your healthcare provider will tell you how to get your results.

Treatment

Chlamydia is treated with antibiotics. Treatment is simple and works very well. You will be given a course of tablets to take, often just a single dose. It is important to finish all the medication exactly as prescribed. Do not have sex for at least one week after treatment (or until your doctor says it is safe) to avoid spreading the infection.

Self-care at home

• Take all the antibiotics as prescribed – even if you feel better
• Avoid sex (vaginal, anal, or oral) for 1 week after treatment
• Tell your sexual partners so they can get tested and treated too
• Drink plenty of water, but do not use any vaginal douches or creams
• You may need to be retested after 3 months to check the infection has gone

Medical treatments

A healthcare provider will prescribe a short course of antibiotics, usually tablets taken by mouth. The most common treatment is a single dose or a week-long course. Your partner(s) should also be treated to prevent reinfection. Do not share your medication with anyone.

When is surgery considered?

Surgery is not used to treat chlamydia. In rare cases, if the infection causes severe complications like an abscess in the fallopian tubes, surgery might be needed. Your doctor will discuss this if it applies.

Living with this condition

Once treated, chlamydia usually goes away completely. You can return to your normal activities after finishing treatment. Until then, avoid sex. If you have symptoms, they should improve within a few days. Follow up with your doctor as advised.

Lifestyle tips

• Use condoms every time you have sex to prevent reinfection
• Limit your number of sexual partners
• Get tested regularly if you are under 25 or have new partners
• Talk openly with partners about sexual health

Diet and exercise

There is no special diet or exercise needed for chlamydia. A healthy balanced diet and regular exercise can support your overall immune system, but they do not treat the infection. Focus on taking your antibiotics and following your doctor's advice.

Mental health and emotional wellbeing

A chlamydia diagnosis can cause worry or embarrassment. It is important to remember that it is a common and treatable infection. You are not alone, and there is no reason to feel ashamed. Talk to a trusted friend or a sexual health advisor if you are feeling anxious.

Prevention

Yes, chlamydia can be prevented. The most effective way is to use condoms correctly every time you have vaginal, anal, or oral sex. Limiting the number of sexual partners and getting tested regularly also lowers your risk.

Screening programmes

Routine screening for chlamydia is recommended for all sexually active people under 25 in the UK. You can get tested at sexual health clinics, some GP surgeries, or order a home test kit online. Testing is free and confidential.

Complications

If left untreated

• In women: pelvic inflammatory disease (PID), which can cause chronic pelvic pain and scarring of the fallopian tubes, leading to infertility or ectopic pregnancy
• In men: epididymitis (inflammation of the tube that carries sperm), which can cause pain and rarely affect fertility
• In both: reactive arthritis (painful joints, eyes, or urethra)
• Increased risk of getting or spreading HIV
• Pregnant women: can pass infection to newborn, causing eye infections or pneumonia

Long-term outlook

The outlook is excellent. Chlamydia is easily cured with antibiotics. Most people have no long-term problems if treated early. Even if complications have already started, treatment can stop further damage. The key is to get tested and treated as soon as possible. You can fully recover and have a healthy sex life.

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