Diagnosis

To check for a kidney infection, you may be asked for a urine sample. The sample is tested for bacteria, blood or pus. You may have blood in your urine that can only be seen under a microscope.

Your healthcare professional also may take a blood sample for a culture. A culture is a lab test that checks for bacteria or other organisms in your urine and blood.

Other tests may include an ultrasound or a CT scan. And you may have a type of X-ray called a voiding cystourethrography. A voiding cystourethrography uses contrast to take X-rays of the bladder when full and while urinating.

Treatment

Antibiotics for kidney infections

Antibiotics are the first line of treatment for kidney infections. The type of medicine and how long you take it depend on your health and the kind of bacteria found in your urine.

Symptoms of a kidney infection often begin to clear up within a few days of treatment. But you may need to continue antibiotics for a week or longer. Finish taking the full course of antibiotics even if you start feeling better. If you don't take all of the medicine, the kidney infection can come back. Or the infection could get worse and spread to other parts of your body. It could spread to your bloodstream, which can be life-threatening.

Your healthcare professional may want you to have another urine culture test to make sure that the infection has cleared. If the infection is still present, you’ll need to take another course of antibiotics.

Hospitalization for severe kidney infections

If your kidney infection is severe, you may need to be treated in the hospital. Treatment may include antibiotics and fluids through a vein in your arm. How long you stay in the hospital depends on how severe your infection is.

Treatment for recurrent kidney infections

An underlying medical condition such as a misshapen urinary tract can cause repeated kidney infections. If you have repeated kidney infections, you may be referred to a urinary surgeon, called a urologist. If you have a structural issue, you may need surgery to repair it. Rarely, you may be referred to an expert in infectious diseases.

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Lifestyle and home remedies

To help you feel better while you recover from a kidney infection:

  • Apply heat. Place a heating pad on your belly, back or side to ease pain.
  • Use pain medicine. For fever or discomfort, take a pain reliever such as acetaminophen (Tylenol, others). If you have chronic kidney disease, it's best to avoid or limit use of nonsteroidal anti-inflammatory drugs, called NSAIDs, such as ibuprofen (Advil, Motrin IB, others).
  • Stay hydrated. Drinking fluids helps flush bacteria from your urinary tract. Avoid coffee, other caffeinated beverages and alcohol until your infection has cleared. They can worsen the feeling of needing to urinate.

Preparing for your appointment

Typically, you see your regular healthcare professional about signs of a kidney infection. If they suspect that an infection has spread to your kidneys, you may need to see a urologist. A urologist is a doctor who treats conditions that affect the urinary tract.

What you can do

When you make the appointment, ask if there's anything you need to do in advance. Ask if you need to change your diet for any tests you may have.

Make note of:

  • Your symptoms, including any that may seem unrelated to your condition. Also note when they started.
  • Key personal information, including recent life changes, such as a new sexual partner. Include your past medical history.
  • The names of all medicines, vitamins and other supplements you take, including doses.
  • Questions to ask your healthcare professional.

Take a family member or friend along, if possible. They can help you remember everything you talk about with your health professional.

For kidney infection, questions to ask include:

  • What is the likely cause of my kidney infection?
  • What tests do I need?
  • What treatment do I need?
  • Will there be side effects from treatment?
  • Do I need to go to a hospital for treatment?
  • How can I prevent future kidney infections?
  • I have other health conditions. How can I manage them together?
  • Are there brochures or other printed material I can have? What websites do you suggest?

Be sure to ask any other questions that you may think of during your appointment.

What to expect from your doctor

Your healthcare professional is likely to ask you questions such as:

  • What are your symptoms?
  • How long have you had symptoms?
  • Do your symptoms come and go?
  • How bad are your symptoms?
  • Does anything make you feel better?
  • What things make your symptoms worse?
March 13, 2026
  1. Kidney infection (pyelonephritis). National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/kidney-disease/kidney-infection-pyelonephritis. Accessed Feb. 11, 2025.
  2. Kidney infection — Symptoms, treatment and prevention. American Kidney Fund. https://www.kidneyfund.org/all-about-kidneys/other-kidney-problems/kidney-infection? Accessed Feb. 11, 2025.
  3. Hooton TM, et al. Acute complicated urinary tract infection (including pyelonephritis) in adults. https://www.uptodate.com/contents/search. Accessed Feb. 11, 2025.
  4. FAQs: Urinary tract infections (UTIs). American College of Obstetricians and Gynecologists. https://www.acog.org/womens-health/faqs/urinary-tract-infections. Accessed Feb. 11, 2025.
  5. Hooton TM, et al. Urinary tract infections and asymptomatic bacteriuria in pregnancy. https://www.uptodate.com/contents/search. Accessed Feb. 11, 2025.
  6. Ferri FF. Pyelonephritis. In: Ferri's Clinical Advisor 2025. Elsevier; 2025. https://www.clinicalkey.com. Accessed Feb. 11, 2025.
  7. Medical review (expert opinion). Mayo Clinic. Feb. 19, 2025.

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