What is chlamydia?

Chlamydia is a sexually transmitted infection (STI) which can affect both men and women. It can occur in the genitals, anus, throat or eyes. It is is spread through unprotected sex, and is treated with antibiotic medicine.

How common is chlamydia?

There were 200,288 cases reported in England in 2015, which makes it the most common STI. Around 70 percent of cases occur in people under the age of 25.

Is chlamydia more common in men or women?

Chlamydia is more commonly diagnosed in women than it is in men: in 2015, female cases in England totalled 114,509; and male cases 83,794.

However, higher testing rates among women has been cited as a significant factor behind this.

Is chlamydia a bacterial or viral infection?

Chlamydia is a bacterial infection. It is caused by the bacteria C. trachomatis. This bacteria is one of several different types in the chlamydia family.

Does chlamydia cause symptoms?

It can cause symptoms, but in many cases it is asymptomatic (causes no symptoms). Around five in every 10 men and eight in every 10 women infected will display no noticeable signs of infection.

What symptoms can chlamydia cause?

Genital cases of chlamydia can cause:

  • Urethritis (pain or burning when going to the toilet)
  • Irregular discharge from the vagina
  • Discharge from the penis
  • Pain in the lower abdomen
  • Vaginal bleeding during or after sex
  • Heavier periods than normal
  • Intermenstrual bleeding
  • Testicular pain

Rectal cases might cause pain and discharge from the anus.

Where it affects the eyes, patients may develop conjunctivitis (eye redness, pain and inflammation).

Cases of infection in the throat will typically be asymptomatic.

How is chlamydia spread?

Chlamydia is spread through sexual contact, including unprotected vaginal, anal or oral sex. It can also be passed on through the shared use of sex toys.

The bacteria is present in the mucous membrane of an infected individual (this is the soft red tissue inside the vagina, penis, anus, eye or mouth), and in semen and vagnial fluid.

When someone comes into contact with any of the above from an infected person, it is possible for them to contract the infection.

Can I get chlamydia from oral sex?

Yes. Sperm, vaginal fluid and mucous membrane secretions from the anus can carry the bacteria. When a couple engage in unprotected oral sex, it is possible for the chlamydia infection to travel genital-to-mouth or anus-to-mouth.

However, the tissue in the genitals is much more susceptible to infection than that in the mouth and throat; so oral sex is a far less common means of transmission.

Can I get chlamydia from anal sex?

Yes. If the sperm of an infected person comes into unprotected contact with the mucous membranes in the anus, the infection can be passed on. Transmission can also occur in the opposite direction, from the anus of an infected person to the penis of their partner.

Can I get chlamydia from sharing sex toys?

Yes. Where someone either does not clean a sex toy between uses or use a condom to cover it, it is possible for the secretions from vaginal or anal tissue to be transmitted from one person to another.

Can I get chlamydia from kissing?

No. Chlamydia cannot be transmitted through mouth-to-mouth kissing.

Am I more at risk of chlamydia if I’m gay?

Heterosexual men account for a higher percentage of chlamydia cases, but this does not necessarily mean that it is less of a risk for male couples.

Gay men are more susceptible to some STIs, such as syphilis and gonorrhoea, than straight men. Statistics from Public Health England state that men who have sex with men (MSM) accounted for 84 percent of syphilis diagnoses and 70 percent of gonorrhoea diagnoses at sexual health clinics in England in 2015.

The actual number of chlamydia diagnoses among the MSM group (12,805) was higher than the number of syphilis cases (4,192) but lower than the number of gonorrhoea cases (22,408). Men who have sex with men accounted for 21 percent of male cases of chlamydia.

Will condoms stop me from getting chlamydia?

Condoms prevent someone from coming into contact with their partner’s sperm or vaginal fluid, which means that where used correctly, they can help to stop the spread of chlamydia.

While condoms do not 100 percent guarantee to prevent the transmission of STIs, they will drastically reduce the likelihood of passing on chlamydia. If you or your partner are not fully sure of your STI status, it is always better to use condoms.

For those who have received a chlamydia diagnosis, or suspect they have come into contact with the infection, you should refrain from having sex, protected or unprotected, until you have been tested and received the appropriate treatment.

Will the pill stop me from getting chlamydia?

No. While it is 99 percent effective at preventing pregnancy, the contraceptive pill offers no protection from STIs, including chlamydia.

Will the withdrawal method stop me from getting chlamydia?

No. The bacteria which causes chlamydia is carried in sperm and vaginal fluid, and is present in the mucous membrane secretions of an infected individual. This means that someone does not necessarily need to ejaculate in order to pass on (or pick up) the infection. Chlamydia may be transmitted through small secretions of sperm or vaginal fluid prior to climax (sometimes referred to as ‘pre-cum’) or through contact with infected tissue.

How can I tell if I have chlamydia?

The only way to tell if you have chlamydia is to get tested.

Even in cases where symptoms indicative of chlamydia are present, these can often be mistaken for other STIs, so you will still need to get tested to both confirm the diagnosis and rule out other infections.

Can you tell if someone else has chlamydia?

In the majority of cases, no. The condition is asymptomatic in 50 percent of men and 80 percent of women, which means that it is often not possible to know whether someone else has chlamydia, based on appearance alone. Getting tested is the only way to be sure.

What does chlamydia testing involve?

Testing typically entails providing a urine sample, or a swab of the vagina or tip of the penis.

A swab may also be taken from the rectum in cases where someone has had anal sex.

Where can I get tested for chlamydia?

There are several places that offer testing for chlamydia and other STIs, including:

  • GUM clinics
  • Sexual health clinics
  • Contraceptive clinics
  • and GP surgeries.

In some parts of England, patients may also be eligible to have self-sampling kits sent to them as part of the National Chlamydia Screening Programme.

You can locate nearby services on the NHS website.

Can I test myself for chlamydia at home?

Yes. There are testing kits available which enable patients to provide the necessary samples at home, and send these to a laboratory for analysis.

However, it’s important to use a test kit supplied by either the NHS or a reputable provider, such as freetest.me.

How long does it take for chlamydia test results to come back?

Results will normally come back in less than two weeks. Where testing is undertaken at a GUM clinic, the patient will usually be notified by their preferred means, be it text message or a phone call, if they need to return for treatment.

If a patient has not heard their result by a certain time, they can usually call a number provided by the clinic to confirm a negative result.

Do I have to tell my partner(s) if I have chlamydia?

Your partner(s) need to be informed if you have received a chlamydia diagnosis, or have symptoms indicative of chlamydia.

Healthcare providers, such as GUM clinics, can help you with partner notification. When doing so, they are required to exercise anonymity on your behalf.

How can I get rid of chlamydia?

The only way to get rid of chlamydia is with antibiotic treatment. A doctor will issue this if you:

  • have taken an STI test and tested positive for chlamydia;
  • or have symptoms that strongly indicate you have chlamydia. In this case, you will still need to take an STI test to confirm the diagnosis.

The first line treatments in the UK for chlamydia currently are Azithromycin and Doxycycline.

Azithromycin is given as a one-off dose, whereas Doxycycline is given as a one week course.

Second-line treatments include Erythromycin, Ofloxacin and Amoxicillin. These might be issued in cases where Azithromycin and Doxycycline are contraindicated.

Because Doxycycline is not suitable to treat chlamydia during pregnancy, a doctor may choose to prescribe Azithromycin, Erythromycin or Amoxicillin.

Can I start taking treatment for chlamydia before I get tested?

In certain cases, a doctor may decide to prescribe antibiotic treatment before waiting for the test result to confirm the diagnosis. These will typically be cases where symptoms that closely resemble those of chlamydia are present.

Even where chlamydia is strongly suspected, however, the patient will still need to undertake an STI test to make sure. This will also be used to rule out other STIs that present similar symptoms to chlamydia.

The partner(s) of someone who has tested positive for chlamydia will usually be advised to begin treatment before confirmation in test results.

How long does treatment take to work?

In most cases, the infection should clear up within a week or two of taking antibiotic treatment. Usually, urinary pain and discharge will start to get better within a week, however other symptoms, such as intermenstrual bleeding can take up to four weeks to improve.

Where symptoms do not get better, you should go back to your doctor for further guidance.

Will I need to be tested for chlamydia again following treatment?

Only in some cases is a ‘test of cure’ (or a test to make sure the infection has gone) for chlamydia recommended. Your healthcare professional will tell you if you need to take another test after treatment.

How long do I need to wait before having sex again after chlamydia?

You should wait for at least seven days following completion of treatment, and the disappearance of symptoms where present, before engaging in sexual intercourse.

If your partner has started treatment for chlamydia after you, or not yet commenced treatment, you should wait until at least seven days after they have completed treatment too.

Can you get chlamydia more than once?

Yes. It is possible to get chlamydia several times. Taking treatment for one infection does not make you immune to further episode; even if you have had chlamydia and taken the treatment as directed by your doctor, you are susceptible to getting the infection again if you have unprotected sex with an infected person.

For more on safe sex practices and reducing the risk of chlamydia, take a look at our prevention methods information page.

Page last reviewed:  25/04/2017