Quick read
Key points
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A kidney infection (pyelonephritis) usually develops when bacteria travel from the bladder up into one or both kidneys, often starting as a urinary tract infection that spreads further. It typically causes back or side pain, fever, chills, and sometimes nausea or vomiting, alongside urinary symptoms.
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Topic-specific prevention and risk reduction will be added during the article-specific evidence audit.
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You have back or side pain alongside urinary symptoms
01 · Know
What is Kidney Infection (Pyelonephritis)?
A kidney infection (pyelonephritis) usually develops when bacteria travel from the bladder up into one or both kidneys, often starting as a urinary tract infection that spreads further. It typically causes back or side pain, fever, chills, and sometimes nausea or vomiting, alongside urinary symptoms.
Kidney infections need prompt treatment with antibiotics, since untreated infection can potentially lead to more serious complications, including kidney damage or a bloodstream infection. Most people recover well with timely, appropriate treatment.
02 · Understand
Clinical context
Back or side pain distinguishes this from a simple bladder infection
The presence of back or side pain and fever, rather than just the burning and frequency of a simple bladder infection, is what typically suggests the infection has spread to affect a kidney.
03 · Act
When to See a Doctor
- 1You have back or side pain alongside urinary symptoms
- 2You have fever, chills, or feel generally unwell with these symptoms
- 3You're pregnant and develop any of these symptoms
- 4Symptoms of a bladder infection aren't improving with treatment
04 · Prevent & manage
Practical steps
This Needs Prompt Antibiotic Treatment, Not Just Home Remedies
A kidney infection needs antibiotics to treat properly and prevent complications — this isn't something to manage with home remedies alone, so prompt medical assessment is important.
- 1See a doctor promptly for suspected symptoms.A urine test can confirm the infection and appropriate antibiotics can be started.
- 2Complete the full course of antibiotics.This is essential for fully clearing the infection and preventing complications.
- 3Drink plenty of water.This supports the kidneys and helps flush the infection.
- 4Take paracetamol for fever and discomfort.This can help manage symptoms while the antibiotics take effect.
- 5Seek urgent care if symptoms worsen or you can't keep fluids down.This may indicate the need for hospital treatment.
Medical information notice
Health education, not individual medical advice
BarnMD Health Library provides general health education for public health literacy. Reading this article does not establish a doctor-patient relationship and this information is not a diagnosis, prescription, or personalised treatment plan. If you have symptoms or concerns about your health, seek appropriate advice from a qualified healthcare professional. If you develop emergency warning signs, seek urgent or emergency medical attention.
BarnMD Bottom Line
Kidney infections need prompt antibiotic treatment, and most people recover well when treatment starts early.
High fever, confusion, or inability to keep fluids down alongside kidney infection symptoms need urgent medical care.