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 your 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 get symptoms, these usually appear between 1 and 3 weeks after having unprotected sex with an infected person. For some people, symptoms might start after many months.
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 not treated, 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.
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 passing urine
- 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 not treated, the infection can cause swelling in the epididymis (the tubes that carry sperm from the testicles) and the testicles. This could affect your fertility.
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)
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.
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 it's not treated, 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 where your joints become sore and swollen.
This is why it's important to get tested and treated as soon as possible if you think you might have chlamydia.
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.
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.
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.