West Australians are being reminded about the importance of practising safe sex, after a significant rise in the number of people diagnosed with gonorrhoea.

A rise in the number of people being diagnosed with gonorrhoea has prompted a warning from WA Health about the importance of practising safe sex.

Notifications of the sexually transmitted infection in Perth have more than doubled in the past five years to 2015, increasing from 684 to 1432.

More than 2000 confirmed cases have already been reported across the state this year, with people aged 20 to 39 accounting for most incidents.

Paul Armstrong, from WA Health, said the sharp increase in gonorrhoea notifications showed the safe sex message was not getting across.

"Gonorrhoea was once an infection that disproportionally affected Aboriginal people and gay and homosexually active men, however a large portion of new cases are spread across heterosexual, and non-Aboriginal men and women in metropolitan Perth," he said.

Dr Armstrong said gonorrhoea would often not show any symptoms so it was important people visited their doctor or sexual health clinic for a test, adding the infection was easily treated with antibiotics.

If not detected and treated early, gonorrhoea can lead to infertility in both men and women, and in rare cases, the infection can spread to the joints, heart and brain, causing permanent damage.