Overview
A kidney infection is a more serious urinary infection in which bacteria travel up from the bladder to one or both kidneys. Unlike a simple bladder infection, it causes fever, chills and pain in the back or side, along with the usual burning urine. It needs prompt antibiotic treatment because, left untreated, it can damage the kidneys or spread into the blood. Pregnant women, children and people with diabetes especially need quick care for these symptoms.
Symptoms
- Fever and chills
- Pain in the back or side, below the ribs
- Burning or pain when passing urine
- Needing to pass urine often and urgently
- Cloudy, bloody or foul-smelling urine, with nausea or vomiting
When to see a doctor
See a doctor promptly for burning urine with fever, chills or back pain — a kidney infection needs antibiotics without delay.
Emergency — call 108 or go to the nearest hospital
- High fever with shaking chills, confusion, a racing heart, very little urine, or inability to keep fluids down — seek emergency care immediately
Causes
Bacteria spreading up from a bladder infection to the kidneys; risk is higher with urine flow blockages, stones, pregnancy, diabetes and a weak immune system.