Chlamydia is the most common sexually transmitted infection in the United Kingdom, which if untreated can damage reproductive (sex) organs. It is sometimes known as 'the silent disease' because many people show no symptoms and don't know they are infected until complications develop.
If symptoms appear, they usually do so one to three weeks after becoming infected. Women may experience a change in vaginal discharge, cystitis (pain when passing water) and mild lower abdominal pain.
If the disease is untreated, it can lead to severe pelvic pain, pain during intercourse or, more rarely, bleeding between periods. Other symptoms may include inflammation of the neck of the womb (cervicitis), inflammation of the fallopian tubes (salpingitis) and inflammation of the glands that produce sexual lubricant mucus (bartholinitis).
Roughly half of all men who get chlamydia show symptoms. These symptoms include a discharge from the penis, inflammation of the tube leading from the bladder to the tip of the penis (urethritis) or inflammation of the tube leading from the testis to the penis (epididymitis). Men may also experience pain or burning when passing urine.
The infection is passed from person to person during unprotected sexual activity ( including during oral, vaginal, or anal sex). Anyone who is sexually active can contract chlamydia. It can also be passed from an infected mother to her baby during normal vaginal delivery.
Laboratory tests are carried out on swabs taken from the cervix (neck of the womb) or from the penis, or by testing urine samples.
The National Chlamydia Screening Programme (NCSP), which is gradually being introduced across England, offers screening for chlamydia to men and women under 25 years of age.
A simple course of antibiotics can cure the infection. Patients should always complete the full course. It is important to treat the infected person's regular sexual partner at the same time because he or she is probably infected too.
Complications are more difficult to treat, but with e arly diagnosis and treatment the risk of getting complications is greatly reduced. With early treatment, the bacteria are eradicated in more than 95 per cent of cases.
Practicing safe sex, by using a condom during sexual intercourse, will reduce the risk of contracting chlamydia. Having sex with fewer partners also reduces the risk of infection.
Complications can occur if a chlamydial infection persists for a long time without treatment. They are most common and most severe in women and include:
More than one third of babies born to infected women develop eye or lung infections and there is.some evidence which shows that untreated chlamydial infections in pregnant women can lead to premature delivery.
A chlamydial infection is often present with other sexually transmitted infections. It is advisable to check if another infection is present. People with infections should abstain from sexual intercourse until they and their partners have been successfully treated. If someone cannot abstain, then a BSI kite-marked (BS EN 600) condom should be used for all sexual intercourse.
We are responsible for collecting and analysing information about chlamydia, looking for any patterns and trends in the disease, which could help with treatment and prevention.
More information about chlamydia is available on our website.
If you have concerns about your health contact NHS Direct on 0845 4647 or visit the website www.nhsdirect.nhs.uk, or see your family doctor.
This factsheet can also be Chlamydia (PDF, 123 KB)
Last reviewed: 27 April 2009