Key Points about Kidney Infection (Pyelonephritis)

  • Bacteria that enter your body cause kidney infections.
  • If not quickly treated, kidney infections can cause permanent kidney damage.
  • Treatment for kidney infections involves a course of antibiotics and hospitalization, if severe.


A kidney infection – also known as pyelonephritis – begins in your urethra (tube that carries urine out of the body) or bladder, and then spreads to one or both kidneys. If you believe you have a kidney infection, you should immediately seek the attention of an experienced kidney specialist. If not quickly diagnosed and effectively treated, pyelonephritis can lead to serious complications, including permanent kidney damage.

Kidney infection causes 

Bacteria cause kidney infections. The bacteria may enter your urinary tract through your urethra or spread from another area of infection in your body. Sometimes, a kidney infection can develop after kidney surgery.

Kidney infection risk factors

Factors that put you at an increased risk for developing a kidney infection include:

  • Being female
  • Having a blockage in the urinary tract, such as a kidney stone
  • Having a weakened immune system
  • Having an enlarged prostate gland
  • Having damage to nerves around the bladder
  • Having diabetes
  • Having HIV
  • Having spinal cord damage
  • Having vesicoureteral reflux (condition that causes urine to flow the wrong direction)
  • Taking certain medications, such as anti-rejection medication for a transplanted organ
  •  Using a urinary catheter (tube to remove urine from your body) for a period of time

Kidney infection symptoms

Signs and symptoms of pyelonephritis can include:

  • Abdominal pain
  • Blood in the urine (hematuria)
  • Burning feeling or pain when you urinate
  • Chills
  • Cloudy urine
  • Fever
  • Frequent, strong urge to urinate
  • Pain in your back, side or groin
  • Pus in the urine
  • Nausea
  • Vomiting
  • Urine with a foul odor

Kidney infection diagnosis

Your specialist will use one or more of the following diagnostic tools to diagnose a kidney infection:

  • Physical exam. Your specialist will complete a physical exam and ask you about your symptoms and history related to your kidney infection.
  • Blood tests. Your specialist will obtain a sample of your blood for close analysis in the lab. If your blood contains bacteria or other organisms, you may have a kidney infection.
  • Imaging tests. Your specialist may order imaging tests – such as an ultrasound, computed tomography (CT) scan, or cystourethrogram – to obtain detailed images of your bladder.
  • Urine tests. Your specialist will obtain a sample of your urine for close analysis in the lab. Lab technicians can determine if your urine contains bacteria or other abnormalities that are signs of an infection. 

Kidney infection treatment

Antibiotic medications are the primary treatment for kidney infections. Your kidney specialist will determine the exact type and dose of antibiotics based on the specific type of bacteria found in your urine tests. Once you are taking antibiotics, you will likely notice symptoms of the infection starting to clear up within a few days. You should continue taking the antibiotic medication for the entire course that your kidney specialist prescribes. You can try home remedies to decrease symptoms of the kidney infection, such as using a heating pad, taking over-the-counter pain medication and drinking plenty of water and clear, caffeine-free and non-alcoholic liquids.

If your kidney infection is severe, you may be admitted to the hospital to receive antibiotics and fluids intravenously, or through a vein in your arm. 

If your kidney specialist determines that an underlying health condition caused your infection, treatment will also focus on managing that condition, so the infection doesn’t come back. 

When should I seek care?

If you experience any of these symptoms, start by voicing your concerns and symptoms to your primary care provider. From there, your doctor may suggest seeing a kidney specialist – or nephrologist – for more specialized treatment.

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