Health - SEXUALLY TRANSMITTED INFECTIONS (STIs) - Chlamydia
Chlamydia is the most common STI in the UK and is easily passed on during sex. Most people don't experience any symptoms, so they are unaware they're infected.
In women, chlamydia can cause pain or a burning sensation when urinating, a vaginal discharge, pain in the lower abdomen during or after sex, and bleeding during or after sex or between periods. It can also cause heavy periods.
In men, chlamydia can cause pain or a burning sensation when urinating, a white, cloudy or watery discharge from the tip of the penis, and pain or tenderness in the testicles. It's also possible to have a chlamydia infection in your rectum (bottom), throat or eyes.
Diagnosing chlamydia is done with a urine test or by taking a swab of the affected area. The infection is easily treated with antibiotics, but can lead to serious long-term health problems if left untreated, including infertility. 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.
Symptoms of chlamydia
Most people with chlamydia don't notice any symptoms and don't know they have it.
If you do develop symptoms, you may experience:
- pain when urinating
- unusual discharge from the vagina, penis or rectum (back passage)
- in women, pain in the tummy, bleeding during or after sex, and bleeding between periods
- in men, pain and swelling in the testicles
If you think you're at risk of having an STI or have any symptoms of chlamydia, visit your GP, community contraceptive service or local genitourinary medicine (GUM) clinic to get tested.
Symptoms of 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.
Symptoms in women
At least 70% of women with chlamydia don't notice any symptoms. If they do get symptoms, the most common include:
- pain when urinating
- unusual vaginal discharge
- pain in the tummy or pelvis
- pain or bleeding during sex
- bleeding after sex
- bleeding between periods
- heavier periods than usual
If chlamydia is left untreated, it can spread to the womb and cause a serious condition called pelvic inflammatory disease (PID). This is a major cause of ectopic pregnancy and infertility in women.
Read more about the complications of chlamydia.
Symptoms in men
At least half of all men with chlamydia don't notice any symptoms. If they do get symptoms, the most common include:
- pain when urinating
- white, cloudy or watery discharge from the tip of the penis
- burning or itching in the urethra (the tube that carries urine out of the body)
- pain in the testicles
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 in the rectum, throat or eyes
Chlamydia can also infect:
- the rectum (back passage) if you have unprotected anal sex – this can cause discomfort and discharge from your rectum
- the throat if you have unprotected oral sex – this is uncommon and usually causes no symptoms
- the eyes if they come into contact with infected semen or vaginal fluid – this can cause eye redness, pain and discharge (conjunctivitis)
When to seek medical advice
If you have any symptoms of chlamydia, visit your GP, community contraceptive service or local genitourinary medicine (GUM) clinic as soon as possible. Search for sexual health services near you.
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.
How do you get chlamydia?
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:
- unprotected vaginal, anal or oral sex
- sharing sex toys that aren't washed or covered with a new condom each time they're used
- your genitals coming into contact with your partner's genitals – this means you can get chlamydia from someone even if there is no penetration, orgasm or ejaculation
- infected semen or vaginal fluid getting into your eye
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.
Is chlamydia serious?
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.
Complications of chlamydia
If chlamydia isn't treated, it can sometimes spread and cause potentially serious problems.
Complications in men
Inflammation of the testicles
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.
Reactive arthritis
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.
Complications in women
Pelvic inflammatory disease (PID)
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:
- difficulty getting pregnant or infertility
- persistent (chronic) pelvic pain
- an increased risk of ectopic pregnancy (where a fertilised egg implants itself outside the womb)
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.
Pregnancy complications
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 GP 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.
Getting tested for 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 GP surgery.
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. If you live in England, you're under 25 and you're sexually active, you should get tested for chlamydia every year or when you change sexual partner, as you're more likely to catch it.
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 GP for advice.
Read more about getting a chlamydia test.
How chlamydia is treated
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.
Preventing 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:
- 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.
Common questions
Find answers to some common questions about chlamydia: