NHS Choices - Diagnosing non-gonococcal urethritis
Non-gonococcal urethritis (NGU) is usually diagnosed after tests have been carried out at a specialist clinic.
If you think you have NGU, you should visit your local genitourinary medicine (GUM) clinic or sexual health clinic. These clinics have access to specialist diagnostic equipment that is probably not readily available to your GP.
You can use the 'Find services' directory to find sexual health services in your area. Sexual health services are free and available to everyone regardless of sex, age, ethnic origin and sexual orientation.
There are two tests used to diagnose NGU. Either test can be used, although both may be carried out to ensure the diagnosis is correct.
You may also be offered tests for other STIs, including HIV. It is up to you whether to have these or not, but a test for all infections is recommended. You can discuss this with healthcare professionals at the clinic if you wish.
A swab test involves taking a small sample of fluid from your urethra, which is the tube that carries urine from the bladder to the outside of the body. The sample can then be examined under a microscope to look for evidence of inflammation or bacteria known to cause NGU.
The sample is taken using a swab, which is like a small cotton bud with a plastic loop at the end. The swab is not painful but can feel a little uncomfortable for a few seconds.
You will be asked to provide a urine sample so that this can be tested for bacteria known to cause NGU, such as chlamydia.
You will be asked not to urinate for around two hours before providing a urine sample, because this can help improve the reliability of the test results.
Clinics that have microscope facilities will be able to give you some results the same day. Other clinics may need to send the samples to a laboratory for testing, in which case the test results may not be available for a week or two.
Healthcare professionals at the clinic will tell you how and when you will receive your test results and will arrange your treatment.