Kidney infection, medically referred to as pyelonephritis, is a commonly occurring ailment characterized by passing urine frequently in a short span of time, elimination of pus or blood with urine, discomfort in the groin area, aching in the abdomen and high fever. It usually arises from a urinary tract infection (UTI) that originates in the urethra and bladder, gradually spreading to the kidneys via the tubular structures known as ureters.

Also Read: Urinary Tract Infection (UTI): Causes, Symptoms And Treatment

There are two forms of kidney infection – chronic pyelonephritis which happens relatively only in seldom cases with recurring instances of kidney complaints and acute pyelonephritis, which develops more often and presents with abrupt grave kidney malfunctions, leading to irreversible damage to renal tissues.


The most common reason for a kidney infection is bacteria which invades the urinary tract, thrives and multiplies in the bladder and eventually creates problems in the kidneys. Sometimes, bacterial infections that arise in other parts of the body can spread via blood circulation to the kidneys, triggering pyelonephritis. In very rare instances, a kidney surgery can give rise to complications of kidney infection.

Risk Factors:

Certain aspects make an individual more susceptible to kidney infection, such as:

  • Being a female, since pyelonephritis can develop more often in women than in men
  • Obstructions in the urinary tract, like from kidney stones or an enlarged prostate
  • Vulnerable immune system owing to chronic conditions like diabetes, cancer, HIV
  • Impaired structures of nerves and spinal cord in the region of the bladder
  • Having utilised a urinary catheter during a diagnostic procedure or surgery
  • The pre-existing ailment of vesicoureteral reflux, in which urine flows in the wrong direction backwards from the bladder into ureters and kidneys


The distinguishing symptoms of pyelonephritis or kidney infection consist of:

  • High fever, with body temperatures rising to 102 F or 39 C
  • Abdominal pain
  • Painful burning sensation during urination i.e. dysuria
  • Urine with a cloudy appearance and rancid odour
  • Passing pus or blood in the urine
  • Tendency to urinate very often
  • Body pain
  • Chills
  • Nausea and vomiting

Also Read: Dysuria: Causes, Symptoms And Treatment


The doctor questions the patient about the exact nature of their symptoms and for how long they have been experiencing them. A urine sample is collected, which is then analysed for the presence of pathogenic bacteria, pus, blood. Additionally, a blood sample is taken to look for any signs of infection-causing microorganisms.

Imaging tests of CT scans, ultrasound and radioactive X-ray procedures are also conducted, to identify any cysts or tumours that may be present in the kidneys, ureters, bladder.


If the patient is diagnosed with acute pyelonephritis, the doctor prescribes antibiotics as the first course of treatment to combat the bacteria infecting the kidneys.

Nevertheless, if the kidney infection is very grave and antibiotics are ineffective in alleviating symptoms, then the doctor advises that the patient be hospitalized. Hydrating fluids and antibiotics are given intravenously, with regular monitoring of the blood and urine of the patient, to ensure that the treatment is working and the infection is subsiding.

When chronic pyelonephritis is confirmed in an individual, then antibiotics are not sufficient to treat the repeating instances of kidney infection, which suggests a more serious underlying problem. In such cases, surgical procedures are performed to drain out abscesses blocking the kidney passages or a portion of the kidney is removed employing a nephrectomy, to rectify pyelonephritis in the patient.