Chlamydia is one of the most common sexually transmitted infections (STIs) in the UK.

Chlamydia is one of the most common sexually transmitted infections (STIs) in the UK.

It’s passed on from one person to another through unprotected sex (sex without a condom).

In 2012, 206,912 people tested positive for chlamydia in England. 64% of people diagnosed with chlamydia were under 25 years old.

Read more information about the causes of chlamydia.

Chlamydia symptoms

Most people who have chlamydia don’t notice any symptoms, and so dont know they have it. Research suggests that 50% of men and 70-80% of women dont get symptoms at all with a chlamydia infection. 

Symptoms of chlamydia could be pain when you urinate (pee), unusual discharge from the penis, vagina or rectum or, in women, bleeding between periods or after sex.

Read more information about chlamydia symptoms.

Getting tested for chlamydia

Testing for chlamydia is done with a urine test or a swab test. You dont always have to have a physical examination by a nurse or doctor.

Anyone can get a free and confidential chlamydia test at a sexual health clinic, a GUM (genitourinary medicine) clinic or a GP surgery. Find out more about getting a chlamydia test.

People under 25 years old can also get tested by the National Chlamydia Screening Programme (NCSP). This is often in places such as pharmacies, contraception clinics or colleges.

You can also buy chlamydia testing kits to do at home, however, the accuracy of these tests varies. If you use one of these tests, talk to your pharmacist or GP.

Read more information about diagnosing chlamydia.

Treating chlamydia

Chlamydia is easily treated with antibiotics. You may be given a single dose, or a longer course of antibiotics to take for a week.

Read more information about treating chlamydia.

If chlamydia isn’t treated, the infection can sometimes spread to other parts of your body and lead to serious long-term health problems such as pelvic inflammatory disease and infertility (not being able to have children).

Read more information about complications of chlamydia.

The National Chlamydia Screening Programme

Chlamydia is most common in people under 25 years old, although people of any age can get it. If you are under 25, you can get a free, confidential chlamydia test under the National Chlamydia Screening Programme (NCSP). This offers tests in various places, including some pharmacies. Find your nearest NCSP testing site.

Some NCSP areas may also send chlamydia testing kits to you through the post. You can request these online. Find out about free online chlamydia tests for under 25s.

Find out answers to some common questions about chlamydia:

Most people who have chlamydia don’t notice any symptoms. If you do get signs and symptoms, these usually appear between one and three weeks after having unprotected sex.

Most people who have chlamydia don’t notice any symptoms.

If you do get signs and symptoms, these usually appear between one and three weeks after having unprotected sex with an infected person. For some people the symptoms occur many months later, or not until the infection has spread.

Symptoms in women

Around 70-80% of women with chlamydia dont notice any symptoms. If women do get symptoms, the most common include: 

  • pain when urinating (peeing)
  • a change in vaginal discharge
  • pain in the lower abdomen
  • pain and/or bleeding during sex
  • bleeding after sex
  • bleeding between periods
  • heavier periods than usual

If chlamydia is left untreated in women, it can spread to the womb and cause pelvic inflammatory disease (PID). PID is a major cause of infertility, miscarriage and ectopic pregnancy.

Symptoms in men

Around half of all men with chlamydia dont notice any symptoms. If men do get symptoms, the most common include: 

  • pain when urinating (peeing)
  • discharge from the tip of the penis (this can be a white, cloudy or watery discharge)
  • pain in the testicles

Some men have mild symptoms that disappear after two or three days. Even if the symptoms disappear you will still have the infection and be able to pass it on. If chlamydia is left untreated in men they are at risk of complications of chlamydia such as orchitis (swollen testicles), reactive arthritis, and infertility.

Chlamydia in the rectum, throat or eyes

Chlamydia can infect the rectum, eyes or throat if you have unprotected anal or oral sex. If infected semen or vaginal fluid comes into contact with the eyes you can also develop conjunctivitis.

Infection in the rectum can cause discomfort, pain, bleeding or discharge. In the eyes, chlamydia can cause irritation, pain, swelling and discharge the same as conjunctivitis. Infection in the throat is less common and usually causes no symptoms.

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Chlamydia is caused by bacteria called Chlamydia trachomatis. Chlamydia is a sexually transmitted infection (STI), which means that you get it through having unprotected sex.

Chlamydia is caused by bacteria called Chlamydia trachomatis.

Chlamydia is a sexually transmitted infection (STI), which means that you get it through having unprotected sex (sex without a condom) with someone who has chlamydia.

How you get chlamydia

You can get chlamydia through: 

  • unprotected vaginal sex
  • unprotected anal sex
  • unprotected oral sex
  • your genitals coming into contact with your partners genitals
  • sharing sex toys when they are not washed or covered with a new condom between each person who uses them

Sexual fluid from the penis or vagina can pass chlamydia from one person to another even if the penis does not enter the vagina, anus or mouth. This means you can get chlamydia from genital contact with someone who has the infection even if there is no penetration, orgasm or ejaculation.

It isn’t clear if chlamydia could be passed on by transferring infected semen or vaginal fluid on the fingers, or by rubbing female genitals together.

Chlamydia cannot be passed on through casual contact, including kissing and hugging, or from sharing baths, towels, swimming pools, toilet seats or cutlery.

Infected semen or vaginal fluid can cause conjunctivitis if it gets into someone’s eye.

Chlamydia and giving birth

During childbirth, a woman with chlamydia can pass the infection on to her baby. If chlamydia develops in the baby there might not be any obvious symptoms at first. Chlamydia in a newborn baby can cause inflammation (swelling) and discharge in the baby’s eyes (known as conjunctivitis) and pneumonia. The midwife or GP can arrange a simple swab test for chlamydia from the baby.

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The only way to find out if you have chlamydia is to get tested. You can get tested whether or not you have symptoms.

The only way to find out if you have chlamydia is to get tested. You can get tested whether or not you have symptoms.

What does the chlamydia test involve?

The tests for chlamydia are simple and painless. Most people can have the test carried out using a urine sample. Some people have a swab test (a small cotton bud). The swab is used to gently wipe the area where you might have chlamydia, to collect some cells. The cells are then tested for infection.

The doctor or nurse will explain which is the best test for you to have. You don’t always have to be examined by the doctor or nurse – this will depend on your situation and where you go to get tested.

People who have had anal or oral sex might have a swab taken from their rectum or throat. This isn’t done on everyone.

If you have symptoms in your eye, such as discharge or inflammation, a swab test might be taken to collect cells from your eyelid.

Tests for women

Chlamydia tests on women can be done with a urine sample or swab test. If a woman has a swab test, it can be taken from the cervix, or inside the lower vagina. Occasionally the doctor or nurse may advise you to have a swab test from the urethra (where urine comes out). Usually you can do a lower vaginal swab yourself, although sometimes a nurse or doctor may do it.

If you have had anal or oral sex you might also be offered a swab test taken from the rectum or throat. This isn’t done on everyone.

Cervical screening tests (smear tests) and routine blood tests do not detect chlamydia. You will need to tell the doctor or nurse if you would also like to be tested for chlamydia at the same time.

Tests for men

Men will usually have a chlamydia test on a urine sample. Occasionally, a swab test may be taken from the urethra (the tube where urine comes out) at the tip of the penis.

If you have had anal or oral sex you might also be offered a swab test taken from the rectum or throat. This isn’t done on everyone.

How soon after sex can I get a chlamydia test?

Dont delay getting tested if you think you might have chlamydia.

You can get a chlamydia test at any time whether or not you have symptoms. You might be advised to repeat the test if it was less than two weeks since you had sex, as sometimes the infection could be in its early stages.

It is recommended that you get tested for chlamydia if:

  • you or your partner think you have any symptoms
  • youve had unprotected sex with a new partner
  • you’ve had a split condom
  • you or your partner have unprotected sex with other people
  • you think you have a sexually transmitted infection (STI)
  • a sexual partner tells you they have an STI
  • youre pregnant or planning a pregnancy
  • you have a vaginal examination and your doctor or nurse tells you that the cells of your cervix are inflamed or there is vaginal discharge

Don’t put off having a test for chlamydia – getting diagnosed and treated as soon as possible will reduce the risk of developing any complications of chlamydia. Complications that occur because of long-term chlamydia infection are more difficult to treat.

Where can I get a chlamydia test?

Anyone can get a free confidential chlamydia test at:

  • a sexual health clinic
  • a GUM (genitourinary medicine) clinic
  • your GP surgery
  • most contraceptive clinics

People under 25 years old can also get tested by the National Chlamydia Screening Programme (NCSP). This is often in places such as pharmacies, colleges or young peoples services.

You can go to whichever place is the most comfortable and convenient for you.

You can also buy chlamydia testing kits to do at home. The accuracy of these varies. If you use one of these tests, talk to your pharmacist or GP.

Find your nearest sexual health clinic by searching by postcode or town.

What happens at a sexual health clinic?

Some clinics are walk-in, at others you may need to book an appointment. Ring first to find out.

When you attend a clinic, you will be registered as a patient. This is confidential, and your details will not be passed on to your GP unless you request it.

You will be asked some questions about why you have attended the clinic and your sexual history. Questions might include when you last had sex, whether you used condoms and whether you have had an STI before.

You will be offered routine tests for gonorrhoea, HIV, syphilis and chlamydia. HIV and syphilis are tested using blood samples. Gonorrhoea and chlamydia are tested using either swab or urine tests. 

Read more information about visiting an STI clinic

How reliable is a chlamydia test?

The accuracy of tests varies, depending on the type of test used. Recommended tests are 90-95% sensitive. This means that they will detect chlamydia in most people who have the infection. Some tests you can buy may be less reliable.

Remember that no test is 100% accurate. There is a small chance that a test may show negative even when you have chlamydia. This is called a false negative test result. It is also possible for a test to be positive even when you do not have chlamydia. This is called a false positive test result. Both of these false tests are very rare but can sometimes explain why you get a different result to your sexual partner.

If you are worried about your test result, talk to your doctor, a sexual health adviser or call the FPA helpline on 0845 122 8690.

Do I have to pay for a test?

If you have a test at an NHS Sexual Health clinic, GUM clinic or with the National Chlamydia Screening Programme (NCSP) then your tests and any treatment is free.

If you go to your GP, the test is free but you may have to pay a prescription charge for treatment, unless you qualify for free prescriptions.

If you buy a test from a pharmacy, you will have to pay.

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Chlamydia is usually treated with antibiotics. Antibiotics are very effective for treating chlamydia.

Chlamydia is usually treated with antibiotics. Antibiotics are very effective for treating chlamydia. More than 95 out of 100 people with chlamydia will be cured if they take their antibiotics correctly.

The two most commonly prescribed antibiotics to treat chlamydia are: 

Your doctor may give you different antibiotics if you have an allergy, or are pregnant. A longer course of antibiotics may be used if your doctor is concerned about complications of chlamydia. Other common antibiotics are ofloxacin and erythromycin.

If there is a high chance you have been infected with chlamydia (for example, your partner has been diagnosed with chlamydia and you have had unprotected sex with them) you might be started on treatment before you get your test results.

Pregnant or breastfeeding

Tell your doctor if you are pregnant or breastfeeding, as this will affect the type of antibiotic you can be given. Azithromycin, amoxicillin and erythromycin are all safe for pregnant women to take.

Antibiotics and contraception

Most antibiotics are safe to use with contraception. If you vomit or have severe diarrhoea they may be less effective and put you at risk of pregnancy, especially if you have unprotected sex. 

Read Will antibiotics stop my contraception working? for more information.

Talk to your doctor, sexual health adviser or pharmacist about whether the antibiotics you are given might affect your contraception.

Having sex again

You should not have sex for at least one week after you have finished your antibiotic treatment. You may need to avoid having sex for longer if your sexual partner has not been treated so that you do not become re-infected. You should also avoid having sex until your symptoms have gone.

Side effects of chlamydia treatment

The side effects of antibiotics are usually mild. The most common side effects include: 

  • stomach pain
  • diarrhoea
  • feeling sick
  • vaginal thrush (vaginal yeast infection, also called candida)

Occasionally, doxycycline can cause a skin rash if you are exposed to too much sunlight (photosensitivity).

Treatment for sexual partners

If you test positive for chlamydia, its important that your current sexual partner and any other recent sexual partners are also tested and treated.

In the UK, its advised that you contact any sexual partners youve had within the past six months.

A specialist sexual health adviser can help you to contact all your sexual partners. Sexual health clinics or GUM clinics can contact your sexual partners for you if you prefer. Either you or the clinic can speak to them, or can send them a note (called a contact slip) to let them know that they may have been exposed to a sexually transmitted infection (STI). The note will suggest that they go for a check-up. The note will not have your name on it, and it may or may not say what the infection is. Your confidentiality will be protected.

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Do I need another test to check chlamydia has gone?

If you take all your antibiotics correctly then you should not need a follow-up test. The doctor or nurse will advise you to have a repeat test if:

  • you were treated for chlamydia and you are pregnant
  • you forgot to take any of your medication or did not take it properly
  • you had sex before you and your partner had finished treatment
  • your symptoms have not gone or if they have come back

Read about complications of chlamydia, for example pelvic inflammatory disease in women and urethritis in men.

If chlamydia is not treated, it can sometimes spread and cause long-term problems.

This page explains about:

Complications in women

In women, chlamydia can spread to the womb (uterus), ovaries or the fallopian tubes. This can cause a condition called pelvic inflammatory disease (PID). Women may also develop an inflammation of the cervix (cervicitis), or an infection in the Bartholin’s glands near the vaginal opening. Very rarely women can develop a reactive arthritis.


Chlamydia is one of the main causes of PID in women. PID is an infection of the womb (uterus), ovaries and fallopian tubes. It can cause infertility, persistent (chronic) pelvic pain and it increases the risk of miscarriage and ectopic pregnancy. PID can be treated with antibiotics, and the risk of infertility is reduced if PID is treated early. 

Inflammation of the cervix (cervicitis)

Chlamydia can cause inflammation of the cervix (the neck of the womb), known as cervicitis. Cervicitis often causes no symptoms, but if you do get symptoms these may include: 

  • bleeding during or after sex
  • bleeding between periods
  • discomfort in your lower abdomen
  • vaginal discharge
  • pain during sex

Blocked fallopian tubes

Chlamydia can spread to cause inflammation in the fallopian tubes (known as salpingitis). This can make it difficult for an egg to travel from the ovary to the womb and can make becoming pregnant more difficult. Find out more about conception and getting pregnant.

Even if a fallopian tube is only partially blocked, this will increase the risk of ectopic pregnancy (when a fertilised egg implants outside the womb, usually in a fallopian tube). Blocked fallopian tubes can sometimes be treated with surgery.

Swollen Bartholin’s glands (Bartholinitis)

The glands that produce a womans lubricating mucus during sex are known as the Bartholin’s glands. They sit on either side of the vaginal opening. Chlamydia can cause the glands to become blocked and infected, leading to a Bartholin’s cyst.

The cyst is usually painless, but if it becomes infected it can lead to an abscess. An abscess is usually red, very tender, painful to touch, and can cause a fever. An infected abscess needs to be treated with antibiotics. Very occasionally an operation is needed to drain the abscess.

Complications in men


Urethritis is inflammation of the urethra (urine tube) that runs along the underside of the penis. Symptoms include: 

  • a white cloudy discharge from the tip of the penis
  • pain or a burning sensation when you urinate
  • the urge to urinate often
  • irritation and soreness around the tip of the penis

There are many causes of urethritis but chlamydia infection is the most common. If you have urethritis and the cause is not known then this is called a “non-specific urethritis” (NSU). NSU is often treated with the same antibiotics as chlamydia.


The main symptoms of epididymitis are swelling and tenderness in the epididymis. The epididymis is part of a man’s reproductive system and carries sperm from the testicles. If the testicles are affected it is called epididymo-orchitis.

A chlamydia infection in the epididymis can cause inflammation, swelling and tenderness inside the scrotum (ball sack). A few men will notice that the whole of the scrotum is red and tender. Infection can lead to a build-up of fluid in the affected area, or even an abscess. If left untreated, epididymitis can sometimes lead to infertility.

Reactive arthritis

Chlamydia can cause a reactive arthritis (inflammation of the joints). In some people the arthritis develops as part of a syndrome and they also develop inflammation of the urethra (urethritis) and the eyes (conjunctivitis).

Reactive arthritis is more likely to occur in men than women. Symptoms usually get better in 3-12 months although they can return after this. Symptoms can usually be controlled by painkillers known as non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen. Some people will need to see a joint specialist if their symptoms are severe.

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There are several ways to protect yourself against chlamydia and most other sexually transmitted infections (STIs), such as genital herpes and gonorrhoea.

There are several ways to protect yourself against chlamydia and most other sexually transmitted infections (STIs), such as genital herpes and gonorrhoea.

You can help to prevent the spread of chlamydia by:

  • using a condom every time you have vaginal or anal sex
  • using a condom to cover the penis during oral sex
  • using a dam (a piece of thin, soft plastic or latex) to cover the female genitals during oral sex or when rubbing female genitals together
  • not sharing sex toys

If you do share sex toys, wash them or cover them with a new condom between each person who uses them.

Find out more about chlamydia symptoms and getting tested for chlamydia.

If you think you’re at risk of having an STI, or you have any symptoms, visit your local sexual health clinic to have them checked out. Find your local sexual health services.

You can find out more about all sexual health services, contraception and STIs on the FPA helpline 0845 122 8690 or call the Worth Talking About helpline on 0800 282930 (2pm-10pm every day) for advice on contraception, sexual health and relationships.

Find answers to some common health questions:

Read Sallys story about how she discovered she had chlamydia when she was 16. She describes her symptoms and how she was diagnosed and treated.

Sally Woodall discovered she had chlamydia when she was 16.

I’d had lots of the symptoms of chlamydia since I was 14, but there wasn’t much awareness about it in 1990. I constantly suffered with pains in my back, spotting between periods and heavy periods. But despite lots of visits to my doctor, nobody realised what it was. They thought I was just a normal teenager, and put me on the pill to regulate my periods.

Then, when I was 16, I had an ectopic pregnancy. It emerged that both my fallopian tubes were damaged. The right one was so badly blocked by scarring that I had to have an operation to remove it. But still, nobody considered the fact that it could be caused by chlamydia. 

It wasn’t until I had a smear test after my ectopic pregnancy, and some pre-cancerous cells showed up, that they investigated further and diagnosed chlamydia. I was given a course of antibiotics to clear up the chlamydia. Then I was told I would never conceive if my remaining tube wasnt unblocked. And that was it. It was a bit brutal. I’d always wanted to be a mum, and I was heartbroken. I thought I’d never have a baby.

I now have four children. I had a laparoscopy to clear the scarring out of my tube. But because I thought I couldn’t have children, and I was with a long-term boyfriend, I didn’t bother taking precautions. My first was born when I was 19.  

I hadn’t heard of chlamydia. I only realised what it is when I got older, and it made me feel a bit dirty. Because of the lack of information, I’d been completely unaware that I was putting not only my own health at risk, but also other people’s. 

Read the real story of Julie Dawson, who was diagnosed with chlamydia when she was 18. It had developed into advanced pelvic inflammatory disease (PID).

Julie Dawson was diagnosed with chlamydia when she was 18. It had developed into advanced pelvic inflammatory disease (PID).

By the time I was diagnosed I must have had chlamydia for a couple of years. I was having episodes of such severe pain in the lower area of my abdomen that I kept collapsing. Over a six-week period I was rushed into hospital by ambulance 10 times. I was working at the time but, needless to say, I lost my job.

Nobody could work out what was wrong with me. I had six laparoscopies and my appendix was taken out as a safety measure. In the end, they discovered that I had enormous adhesions, caused by pelvic inflammatory disease. The adhesions were so vast they couldn’t see my womb. My fallopian tubes were so badly damaged I had to have an operation to remove them. I was able to keep my ovaries, thank goodness. 

The adhesions were a direct result of the PID, and they had caused all the acute pain. I hadn’t known much about chlamydia before then. I hadnt even had lots of sexual partners. I’d had one sexual experience, then a long-term boyfriend.

At the time, I was very naive. I didn’t understand the implications of PID or the fact that my tubes were removed. I just let the doctors do what had to be done so that I could get on with life again. But I suffered emotionally when I later realised that I might never have children. 

My husband and I have had three attempts at IVF in order to start a family. Thankfully, I’m now pregnant with twins. 

See what your doctor sees, find out what is happening with your Chlamydia treatment and what the next steps might be.

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Map of Medicine: chlamydia