Often referred to as UTIs, Urinary Tract Infections start when bacteria enter the body through the urethra. You can read more about the causes, prevention and treatment of UTIs here.
Once the bacteria have established, it can travel upwards to the bladder and even on the kidneys, causing a kidney infection.
The infection irritates the tract (and bladder and kidneys if it’s progressed that far) causing a sudden and urgent need to urinate and a painful burning sensation when urine is passed.
Be aware that in children and the elderly, these symptoms may be absent and a general sense of being unwell, with fever and nausea, may be the only indication.
In all cases, UTIs are unlikely to resolve themselves and medical attention should be sought as soon as practicable.