New to Kidney Infection? Start Here
Kidney Infection: the few things that matter most, and the mistakes that catch people out early.
Infection reaching the kidney, usually spreading upward from the bladder.
Key takeaways
- Typical symptoms: fever, shivering, back or flank pain, feeling very unwell
- Distinguishing feature: systemic illness, not just urinary symptoms
- Most useful single change: Seek same-day assessment rather than treating as a simple UTI.
- Commonest mistake: Treating fever with back pain as an ordinary bladder infection.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
Why bother
It is considerably more serious than a bladder infection and can cause sepsis and permanent scarring.
Start here
Just these two to begin with. The rest can wait.
- Seek same-day assessment rather than treating as a simple UTI
- Keep fluids up
Then add these
Once the first two are automatic, these are worth adding.
- Complete the antibiotic course exactly as prescribed
- Ask for investigation after a kidney infection, particularly in men
The numbers, in one place
| Measure | Figure |
|---|---|
| Typical symptoms | fever, shivering, back or flank pain, feeling very unwell |
| Distinguishing feature | systemic illness, not just urinary symptoms |
| Treatment | antibiotics, sometimes intravenous |
| In older adults | confusion may be the main sign |
Common early mistakes
- Treating fever with back pain as an ordinary bladder infection
- Delaying assessment in pregnancy, which raises complication risk
- Stopping antibiotics early
Where to go next
- Making Sense of Kidney Infection
- The Kidney Infection Checklist: What to Do and What to Skip
- Kidney Infection — the reference entry
- Medicines and the Kidneys: Sorting the Evidence From the Noise
- The Evidence on Blood in Urine, Without the Hype
When to speak to a doctor
Seek same-day medical help for urinary symptoms with fever, shivering, back or flank pain, vomiting, or confusion. Call 999 for signs of sepsis: very high or very low temperature, rapid breathing, a racing heart, mottled skin, confusion, or passing no urine for several hours. Urinary symptoms in pregnancy need urgent assessment.
Where this comes from
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.
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