Kidney infection and sepsis: what to know

A kidney infection often develops when bacteria travel up from the bladder through the urinary tract. Fever, chills, pain in the side or back, cloudy urine and painful urination can occur, but symptoms vary. A urine test can help clinicians look for infection and guide treatment.

Sepsis is not a separate type of urine infection. It is the body’s harmful response when an infection disrupts organ function. The risk is more concerning when infection is untreated or urine flow is blocked, and people who are older, pregnant, immunocompromised or living with significant health conditions may become unwell quickly.

Contact a clinician promptly for fever with flank pain, chills, vomiting, or urinary symptoms. Assessment may include vital signs, an examination, urine testing and blood tests. Take prescribed antibiotics exactly as directed and complete the course unless the prescriber changes it. Do not use leftover antibiotics.

Drink according to your clinician’s advice, especially if vomiting, pregnant, or living with kidney or heart disease. Mention recent antibiotics, allergies, pregnancy, catheter use and any difficulty passing urine, as these details can change the assessment.

Seek emergency care for confusion, extreme drowsiness, rapid or difficult breathing, fainting, cold or mottled skin, severe weakness, very little urine, or a rapidly worsening feverish illness. Also seek urgent help when you cannot keep fluids down or have severe side pain with urinary symptoms. Sepsis can worsen quickly and needs hospital assessment.

Ask: Could this be a kidney infection or another source? Do I need a urine test or blood tests? Is urine flow blocked? Which symptoms mean I should go to emergency care, and when should I expect improvement after treatment?