Gonorrhoea is caused by the bacterium, Neisseria gonorrhoeae. This culprit cannot live outside the body, so exchange of bodily fluid is necessary to catch it. Gonorrhoea can be passed on from all types of sex (vaginal, anal and oral sex) and can infect the vagina, cervix, urethra, rectum, throat and even the eye. Gonorrhoea is often detected in the rectum, even when anal intercourse hasn't occurred, due to spread from the genital area.

What symptoms will you notice?
As many as 60 per cent of women and 10 per cent of men do not develop symptoms. If symptoms do occur, the first sign in men is usually a pus-stained discharge from the penis and pain on passing urine - classically described as like passing broken glass or razor blades.

Interestingly, symptoms of gonorrhoea seem to have altered. Infection often now produces milder discharge and less pain on passing urine. So it's important to have even mild, transient symptoms checked out as early as possible.

How is gonorrhoea diagnosed?
By taking swabs from the urethra, cervix, and - if indicated - the throat and rectum. Any discharge is then examined under a light microscope. In gonorrhoea, staining with dyes will reveal pus cells containing groups of bacteria that resemble tiny, paired red kidney beans. As the bacteria are small and easily missed, swabs are also sent for culture.

How is gonorrhoea treated?
With a single dose of antibiotics such as ciprofloxacin, ofloxacin, azithromycin, high dose oral ampicillin or an intramuscular injection of spectinomycin. Gonorrhoea is becoming increasingly resistant to penicillin. Anti-Chlamydia medication may be given, as the two conditions often co-exist.

Due to the possibility of poor treatment response, no sexual activity should occur until at least one repeat swab - and preferably three, taken at weekly intervals - are reported negative.

What happens if gonorrhoea goes untreated?
In women, infection may spread to cause pelvic inflammatory disease (PID) in 10 to 20 per cent of those infected, which can cause difficulty conceiving naturally. Untreated gonorrhoea can be passed from mother to baby during childbirth, to cause conjunctivitis. Gonococcal infection of the eye needs urgent medical treatment as it can cause scarring and blindness if left untreated.

Gonorrhoea can spread to infect the prostate (prostatitis) and testicles (epididymo-orchitis) in up to 10 per cent of men. Chronic infection of the male genital tract can also lead to scarring and persistent difficulty passing urine.

In one per cent of infected men, gonococcal bacteria spread throughout the body to cause a skin rash and gonococcal tendonitis and arthritis. Fever, shivering, loss of appetite, and joint pain can occur, with severe pain on moving. The infection seems to flit from joint to joint initially, but if allowed to progress, pus can build up and joint damage occurs.

Very rarely, gonococci multiply within the blood stream to cause septicaemia. This can lead to infection of the brain or heart valves, shock and even death.

If you're worried you have an STI or want to find out more, check out the symptoms, diagnosis and treatments for:

• Chlamydia
• Genital herpes (HSV)
• Genital warts
• HIV and AIDS
• Pubic lice
• Scabies
• Syphilis
• Trichomonas