When is antibiotic treatment recommended for kidney infection?

A kidney infection, also called pyelonephritis, often starts when bacteria travel from the bladder towards a kidney. Fever, chills, pain in the side or back, nausea and feeling unwell may occur along with burning or frequent urination, but symptoms vary. A clinician may test urine and sometimes blood, then choose an antibiotic based on the illness, allergies, kidney function, previous infections and local guidance. Some people can take tablets at home; others need hospital treatment through a vein if they are very unwell or cannot keep medicine down.

Take the antibiotic exactly as prescribed and complete the planned course unless your clinician gives different instructions. Drink fluids if you can do so safely, rest, and use only pain or fever medicines suitable for you. Do not use leftover antibiotics or delay review because pain briefly improves. If symptoms are not starting to improve, or they return after treatment, contact the prescriber promptly; a urine culture or a change of medicine may be needed. A blockage, stone or prostate problem can sometimes prevent infection from clearing.

Seek emergency help for confusion, fainting, severe weakness, breathing difficulty, persistent vomiting, inability to take fluids or medicine, or rapidly worsening pain and fever. Pregnancy, childhood, older age, kidney disease, diabetes or a weakened immune system can change the urgency, so request same-day medical advice when these apply. Do not wait for a routine appointment if you feel significantly unwell.

Ask whether urine culture was sent, when improvement should begin, which pain medicines are safe with your kidney function, and whether tablets or hospital treatment are more suitable. Ask whether an obstruction needs checking, how to handle a missed dose, and what symptoms mean you should return urgently.