Chlamydia is one of the most common STIs in the UK

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

Getting tested for chlamydia

Testing for chlamydia is done with a urine test or a swab test. You don't 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.

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.

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. 

We can send you a chlamydia testing kits through the post. You can request the kit here


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 don’t 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 don’t 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.

If you’re under 25

If you are sexually active and under 25 years old, you should get tested for chlamydia every year or every time you have a new partner. the National Chlamydia Screening Programme can offer testing near you.


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:

  • azithromycin (single dose)
  • doxycycline (a longer course, usually two capsules a day for a week)

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. 
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, it’s important that your current sexual partner and any other recent sexual partners are also tested and treated.

In the UK, it’s advised that you contact any sexual partners you’ve 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.

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

Anyone who is sexually active can catch chlamydia, especially people who change partners frequently 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.