According to the NHS, most urinary tract infections (UTIs) are mild and resolve quickly with treatment. However, if left untreated or if the infection spreads, complications can occur.
These may include:
Kidney infection (pyelonephritis), which can cause fever, back pain, and feeling very unwell
Recurring UTIs (frequent infections)
In rare cases, sepsis, a serious and life-threatening response to infection
The NHS advises seeking medical attention if symptoms worsen, do not improve with treatment, or if signs of a more serious infection develop.