What causes non-gonococcal urethritis?
• Infection with chlamydia causes about half of cases of NGU. Chlamydia is a bacterium (germ) that is usually caught by sexual contact with an infected person. You can pass chlamydia on during vaginal, anal or oral sex. • Various other bacteria or viruses which are sexually transmitted can cause NGU. • A non-infective problem is, rarely, the cause. For example, injury or surgery to the urethra can cause inflammation. • No cause can be found in about 1 in 4 cases. Sexually transmitted infections that are not identified by tests are probably the cause of some of these, but not all. However, it is not possible to say which of these cases are due to infection and which are not.
