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) and is particularly common in sexually active teenagers and young adults.
If you live in England, are under 25 and are sexually active, it's recommended that you get tested for chlamydia every year or when you change sexual partner.
In 2013, more than 200,000 people tested positive for chlamydia in England. Almost 7 in every 10 people diagnosed with the condition were under 25 years old.
Most people with chlamydia don't notice any symptoms and don't know they have it.
If you do develop symptoms, you may experience:
If you think you're at risk of having an STI or have any symptoms of chlamydia, visit your doctor, community contraceptive service or local genitourinary medicine (GUM) clinic to get tested.
Read more about chlamydia symptoms.
Chlamydia is a bacterial infection. The bacteria are usually spread through sex or contact with infected genital fluids (semen or vaginal fluid).
You can get chlamydia through:
It can also be passed by a pregnant woman to her baby – read about the complications of chlamydia for more information about this.
Chlamydia can't be passed on through casual contact, such as kissing and hugging, or from sharing baths, towels, swimming pools, toilet seats or cutlery.
Although chlamydia doesn't usually cause any symptoms and can normally be treated with a short course of antibiotics, it can be serious if it's not treated early on.
If left untreated, the infection can spread to other parts of your body and lead to long-term health problems, such as pelvic inflammatory disease (PID), epididymo-orchitis (inflammation of the testicles), and infertility. It can also sometimes cause reactive arthritis .
This is why it's important to get tested and treated as soon as possible if you think you might have chlamydia.
Read more about the complications of chlamydia.
Testing for chlamydia is done with a urine test or a swab test. You don't always need a physical examination by a nurse or doctor.
Anyone can get a free and confidential chlamydia test at a sexual health clinic, a genitourinary medicine (GUM) clinic or a doctor surgery.
You can also buy chlamydia testing kits to do at home, although the accuracy of these tests varies. If you do use one of these tests, speak to your pharmacist or doctor for advice.
Read more about getting a chlamydia test.
Chlamydia can usually be treated easily with antibiotics. You may be given some tablets to take all on one day, or a longer course of capsules to take for a week.
You shouldn't have sex until you and your current sexual partner have finished your treatment. If you had the one-day course of treatment, you should avoid having sex for a week afterwards.
It's important that your current sexual partner and any other sexual partners you've had during the last six months are also tested and treated to help stop the spread of the infection.
The NCSP recommends that under 25s who have chlamydia should be offered another test around three months after being treated. This is because young adults who test positive for chlamydia are at increased risk of catching it again.
Sexual health or GUM clinics can help you contact your sexual partners. Either you or the clinic can speak to them, or they can be sent a note advising them to get tested. The note won't have your name on it, so your confidentiality will be protected.
Read more about treating chlamydia .
Anyone who is sexually active can catch chlamydia. You're most at risk if you have a new sexual partner or don't use a barrier method of contraception, such as a condom, when having sex.
You can help to prevent the spread of chlamydia by:
If you do share sex toys, wash them or cover them with a new condom between each person who uses them.
Find answers to some common questions about chlamydia:
Most people who have chlamydia don't notice any symptoms.
If you do get symptoms, these usually appear between one and three weeks after having unprotected sex with an infected person. For some people they don't develop until many months later.
Sometimes the symptoms can disappear after a few days. Even if the symptoms disappear you may still have the infection and be able to pass it on.
At least 70% of women with chlamydia don't notice any symptoms. If they do get symptoms, the most common include:
Read more about the complications of chlamydia.
At least half of all men with chlamydia don't notice any symptoms. If they do get symptoms, the most common include:
If chlamydia is left untreated, the infection can cause swelling in the epididymis (the tubes that carry sperm from the testicles) and the testicles. This could affect your fertility.
Read more about the complications of chlamydia.
Chlamydia can also infect:
If you have any symptoms of chlamydia, visit your doctor or local genitourinary medicine (GUM) clinic as soon as possible.
You should also get tested if you don't have any symptoms but are concerned you could have a sexually transmitted infection (STI).
If you're sexually active and under 25 years old, you should get tested for chlamydia every year or every time you have a new partner. You can get tested in places such as pharmacies, colleges and youth centres.
Read more about getting tested for chlamydia.
The only way to find out if you have chlamydia is to get tested. You can get tested whether or not you have symptoms.
If you live in England, you're under 25 and you're sexually active, it is recommended that you get tested every year or when you change sexual partner, as you're more likely to catch chlamydia.
The recommended tests for chlamydia are simple, painless and generally very reliable.
They involve sending a sample of cells to a laboratory for analysis. You don't necessarily have to be examined by a doctor or nurse first and can often collect the sample yourself.
There are two main ways the sample can be collected:
Men will usually be asked to provide a urine sample, while women will usually be asked to either swab inside their vagina or provide a urine sample.
The results will normally be available after 7 to 10 days. If there's a high chance you have chlamydia – for example, you have symptoms of the infection or your partner has been diagnosed with it and you've had unprotected sex with them – you might start treatment before you get your results.
Read more about treating chlamydia.
Don't delay getting tested if you think you might have chlamydia. Being diagnosed and treated as soon as possible will reduce your risk of developing any serious complications of chlamydia.
You can get a chlamydia test at any time, although you might be advised to repeat the test later on if it was less than two weeks since you had sex as the infection might not always be found in the early stages.
You should consider getting tested for chlamydia if:
If you're under 25 years of age and sexually active, getting tested every year or when you change sexual partner is recommended because you're more likely to catch chlamydia.
If you have chlamydia, you also should be offered another test around three months after being treated. This is because young adults who test positive for chlamydia are at increased risk of catching it again.
You can get a free, confidential chlamydia test at:
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, but these aren't always very accurate. If you're considering using one of these tests, speak to your pharmacist or doctor for advice.
Chlamydia can usually be effectively treated with antibiotics . More than 95% of people will be cured if they take their antibiotics correctly.
You may be started on antibiotics once test results have confirmed you have chlamydia. But if it's very likely you have the infection, you might be started on treatment before you get your results.
The two most commonly prescribed antibiotics for chlamydia are:
Your doctor may give you different antibiotics, such as amoxicillin or erythromycin, if you have an allergy or are pregnant or breastfeeding. A longer course of antibiotics may be used if your doctor is concerned about complications of chlamydia.
You shouldn't have sex – including vaginal, oral or anal sex, even with a condom – until both you and your partner(s) have completed treatment.
If you had the one-day course of azithromycin, you should avoid having sex for a week after treatment.
This will help ensure you don't pass on the infection or catch it again straight away.
If you take your antibiotics correctly, you may not need to return to the clinic.
However, you will be advised to go back for another chlamydia test if:
If you're under 25 years of age, you should be offered a repeat test for chlamydia three months after finishing your treatment because you're at a higher risk of catching it again.
If you test positive for chlamydia, it's important that your current sexual partner and any other sexual partners you've had during the past six months are also tested and treated.
A specialist sexual health adviser can help you contact your recent sexual partners, or the clinic can contact them for you if you prefer.
Either you or someone from the clinic can speak to them, or the clinic can send them a note to let them know they may have been exposed to a sexually transmitted infection (STI).
The note will suggest that they go for a check-up. It will not have your name on it, so your confidentiality will be protected.
If chlamydia isn't treated, it can sometimes spread and cause potentially serious problems.
In men, chlamydia can spread to the testicles and epididymis (tubes that carry sperm from the testicles), causing them to become painful and swollen. This is known as epididymitis or epididymo-orchitis.
The inflammation is usually treated with antibiotics. If it's not treated, there's a possibility it could affect your fertility.
Chlamydia is the most common cause of sexually acquired reactive arthritis (SARA). This is where your joints, eyes or urethra (the tube urine passes out of the body through) become inflamed, usually within the first few weeks after having chlamydia.
It can affect women who have had chlamydia, but is more common in men.
There's currently no cure for SARA, but most people get better in a few months. In the meantime, treatment with non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen can help relieve the symptoms.
In women, chlamydia can spread to the womb, ovaries or fallopian tubes. This can cause a condition called pelvic inflammatory disease (PID).
PID can cause a number of serious problems, such as:
The symptoms of PID are generally similar to the symptoms of chlamydia, including discomfort or pain during sex, pain during urination, and bleeding between periods and after sex.
PID is usually treated with a two-week course of antibiotics. The risk of experiencing problems such as infertility is lower if it's treated early, so it's important to seek medical advice as soon as possible if you have symptoms of the condition.
If you have chlamydia that's not treated while you're pregnant, there's a chance you could pass the infection on to your baby. If this happens, your baby may develop an eye infection (conjunctivitis) and lung infection (pneumonia).
If your baby has symptoms of these conditions, your midwife or doctor can arrange for a test to check for chlamydia and antibiotics can be used to treat the infection.
Untreated chlamydia in pregnancy may also increase the risk of your baby being born prematurely (before 37 weeks of pregnancy) or with a low birth weight, and might mean you're more likely to have a miscarriage or stillbirth.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.