If a gonorrhoea infection remains untreated, it can spread to your blood and joints and become life-threatening. It It also decreases your fertility over time, eventually leading to infertility if it's not properly diagnosed and treated in its early stages. Gonorrhoea also puts you at a greater risk of contracting HIV and AIDS because your body's good bacteria try to fight off the STI, leaving it vulnerable to other infections.
The infection can also cause epididymitis in men, which causes a painful inflammation in the ducts of the testicles, and may lead to infertility.
In women it increases the chance of an ectopic pregnancy, where a fertilised egg implants itself outside of the womb, often in the fallopian tubes. As the pregnancy progresses, the fallopian tubes stretches which can cause considerable abdominal pain and discomfort. If it's not treated in time the fallopian tube can burst, causing internal bleeding and can even lead to death.