Overview
A kidney infection is a bacterial infection that has usually travelled up from the bladder into one or both kidneys. It is more serious than a simple bladder infection and can make you quite unwell quickly. Prompt medical attention is important to prevent complications.
Symptoms
- Pain in the back or side, below the ribs
- Fever and chills
- Nausea or vomiting
- Burning or pain when urinating
- Frequent or urgent need to urinate
- Cloudy, bloody or foul-smelling urine
- Feeling generally very unwell
Causes & risk factors
- Bacteria spreading upward from a bladder infection
- Blockage in the urinary tract, such as a kidney stone
- An enlarged prostate restricting urine flow
- Urinary catheter use
- Conditions that weaken the immune system
- Pregnancy, which can slow urine flow
Treatment & self-care
A clinician confirms the diagnosis with urine and sometimes blood tests and treats the infection, often with prompt antibiotic therapy chosen and dosed by the clinician. Imaging may be done if a blockage or stone is suspected. Severe cases may need hospital care for fluids and closer monitoring. Always have a suspected kidney infection assessed by a licensed clinician.
See a doctor urgently if
- You have back or side pain with fever, chills, or vomiting
- Urinary symptoms are not improving or are getting worse
- You are pregnant and have any urinary symptoms
- Seek emergency care for confusion, very high fever, inability to keep fluids down, or feeling faint, as these can signal the infection spreading to the blood
This condition can be an emergency. If any of the signs above are severe or getting worse, go to the nearest emergency room now or call your local emergency number — do not wait for an online consultation.