Urethritis is inflammation (pain, redness and/or swelling) of the urethra (tube where urine comes out). Sometimes it is called non-specific urethritis (often known as NSU) or non-gonococcal urethritis (NGU). This means inflammation of the urethra when the cause is not yet known and the sexual infection gonorrhoea (which can cause inflammation) has been ruled out. It is possible for men and women to have non-specific urethritis but it is more difficult to diagnose in women.
For more info please go to: http://www.fpa.org.uk/Helpandadvice/SexuallytransmittedinfectionsSTIs/Non-specificurethritis