How to know if UTI has spread to kidneys?
Signs a UTI has spread to the kidneys include high fever, chills, back or side pain, nausea, vomiting, and feeling very unwell. Seek urgent medical care if these occur.
Detailed Medical Explanation
When a UTI spreads to the kidneys (pyelonephritis), symptoms escalate. You may experience a high fever (above 38°C), severe pain in your back or side (flank), nausea, vomiting, chills, and generally feeling very ill. These symptoms suggest a more serious infection that requires immediate antibiotics and possibly hospital treatment. NHS: Signs UTI spread to kidney.
Clinical Context
Clinics treat kidney infections urgently. Any severe UTI symptoms plus fever, vomiting, or back pain warrant rapid clinical assessment.
Evidence-Based Approaches
NHS and NICE highlight red flag symptoms—such as fever, flank pain, and vomiting—as requiring same-day review for pyelonephritis.