Non-specific urethritis (NSU)

Non-specific urethritis (NSU) is one of the most common sexually transmitted infections in men.

‘Urethritis’ means ‘inflammation of the urethra’ (the tube inside the penis that urine comes down). ‘Non-specific’ means the exact cause of the inflammation isn’t known, but it is caused by bacteria (often chlamydia) picked up from a partner’s mouth, vagina, rectum or penis during sex. Sometimes doctors call it non-gonococcal urethritis or NGU.

Women do not contract NSU but, as with most sexually transmitted infections, if her partner contracts NSU the woman will also be offered treatment.



There may be no symptoms but up to three weeks after becoming infected a man might get a whiteish discharge from his penis.

He might also feel an itching or burning inside his penis, especially when urinating.


How it’s passed on

NSU is usually caused by bacteria. They live inside a partner’s mouth, vagina, penis or rectum and get into a man’s penis when he has unprotected oral, vaginal or anal sex. He might also carry the bacteria on his fingers to his penis after touching an infected part of his own or someone else’s body.

Using condoms cuts the risk of NSU, which can also be caused by unprotected oral sex. Sometimes NSU is inflammation caused by friction from masturbation and sex, or even a reaction to things like soap.

If a man has HIV, having untreated NSU makes it more likely he’ll pass on HIV during unprotected sex.


Tests and treatment

There’s a urine test for NSU or a sample can be taken from the opening of the penis using a swab (small cotton bud). This might be uncomfortable for a second or two.

A course of antibiotics will cure NSU. Sex should be avoided until you have finished your treatment to avoid passing it on. Sexual partners also need to be checked – a clinic can contact them anonymously. Untreated NSU sometimes causes serious problems such as arthritis or infertility.

Most people get tested and treated for infections like NSU at sexual health (or ‘GUM’) clinics. It is free and confidential – no one else, including your GP will be told about your visit. Some GP surgeries also test for and treat these infections.

The more people you have sex with, especially unprotected sex, the more chance you have of getting infections like NSU. You can have them without knowing so regular check-ups are a good idea, especially if you are starting a new relationship and/or you want to stop using condoms with your partner.


Page content supplied by Copyright 2012 © Terrence Higgins Trust.

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