Kidney Infection

1 What is a Kidney Infection?

Kidney infection (or pyelonephritis) is caused when pathogenic bacteria infects the kidney. It may occur when a urinary tract infection (UTI) reaches the kidney through the urethra(the tube which carries urine from the urinary bladder to excrete through the urethral opening) .

The bacteria travel through the skin around the ureter (tubes connecting the kidneys to the urinary bladder for urine transport) and reach the kidney to cause the infection. An immediate medical attention is required in case of a kidney infection.

It can cause a severe and permanent damage to the kidneys or the bacteria may infect the bloodstream which can cause a lethal infection. The treatment usually involves administration of antibiotics and the patient may often require to being hospitalized.

2 Symptoms

Signs and symptoms of a kidney infection may include:

  • Fever
  • Pain in back, side or groin area
  • Abdominal pain
  • Frequent urination
  • Strong, persistent urge to urinate with a burning sensation
  • Pain during urinating
  • Pus or blood in urine
  • Foul smell from urine
  • Cloudiness in appearance of urine

Severe kidney infection can lead to lethal complications thus look for immediate medical attention if you experience a typical kidney infection symptom combined with bloody urine or nausea and vomiting.

3 Causes

The entry of the bacteria through the tube that carries urine (called ureter) into the urinary tract causes a kidney infection.

Bacteria from an infection in other parts of the body can also infect the bloodstream and reach the kidneys.

Although it is an unusual case, it can happen if the patient has an artificial joint or heart valve that becomes infected. In rare cases, kidney infection results after kidney surgery.

4 Making a Diagnosis

Consult your family doctor or a general practitioner to make a diagnose of a kidney infection. You may further be referred to a doctor who treats conditions that affect urinary tract (urologist).

It is recommended that the patient should make a note of key personal information like recent life changes (if involved with a new sexual partner), related or unrelated symptoms, medication which a patient is taking. If possible, take a friend or a family member with you.

Doctors usually diagnose kidney infections based on signs and symptoms, such as fever or back pain. If your doctor suspects that you have a kidney infection, he/she may ask you to provide a urine sample to test it for bacteria, blood or pus.

The doctor may test the urine to obtain a blood culture to check for bacteria or other organisms in your blood. Other diagnostic tests for confirmation of kidney infection might include an ultrasound, computerized tomography scan or a type of X-ray known as a voiding cystourethrogram.

5 Treatment

Administration of antibiotics is the first step in treatment for kidney infections. The drugs which you use and the duration of the medication depends on your health condition and the bacteria found in your urine tests.

Usually, it takes less time to clear up the signs and symptoms of a kidney infection. But you may need to continue antibiotics for a week or longer. You are advised to take the entire course of antibiotics recommended by the doctor to ensure that the infection is completely eliminated.

In the case of a severe kidney infection, the patient may need to be hospitalized and the patient may need to be treated by injecting antibiotics through intravenous route. The duration of hospitalization varies with the severity of the condition.

Recurrent kidney infections may result from other underlying medical problems, such as a structural abnormality. If needed, the doctor may refer you to a nephrologist (kidney specialist) or a urologist (urinary surgeon) for determining if any urologic abnormality is the cause of your problem. You may need surgery to repair a structural abnormality.

6 Prevention

Following steps has to be taken to prevent a kidney infection, especially in women:

  • Drink plenty of fluids, especially water. It helps flush the bacteria out from your body through urine.
  • Urinate frequently
  • Urinate after intercourse
  • Wipe from front to back after urinating or defecation. It helps to prevent bacteria from spreading to the kidney through the urethra.
  • Avoid using toxic products like deodorant sprays or douches in your genital area as they can irritate your urethra.

7 Lifestyle and Coping

Maintaining a healthy lifestyle is the best way to cope with a kidney infection.

For the reduction of discomfort while recovering from a kidney infection, you might:

  • Use a heating pad on your abdomen, back or side to reduce feelings of pressure or pain.
  • Use painkillers
  • For fever or discomfort, take a non-aspirin pain reliever as directed by your doctor
  • Stay hydrated as much as possible. Drinking plenty of fluids will help flush bacteria from your urinary tract.
  • Don’t drink coffee or alcohol until your infection has cleared, as these decrease the water levels in your body and act as anti- diuretics. These products can aggravate a frequent or urgent need to urinate.

8 Risks and Complications

Factors that increase the risk and complications of a kidney infection include:

  • Female anatomy: Women comparatively, are at a greater risk of kidney infection than men as they have a shorter urethra and the bacteria have less distance to travel from outside of the body to the bladder.
  • Pregnant women are at a very risk of catching a kidney infection.
  • Any blockage in the urinary tract such as blockage due to structural abnormalities or stones in your urinary system or an enlarged prostate gland (in men) can increase the risk of kidney infection.
  • Weak immune system: Medical conditions that attenuate your immune systems, such as diabetes and HIV, increase the risk of kidney infection or the drugs which are taken to suppress the immune system for preventing rejection of the transplanted organs.
  • Damage to nerves around the bladder.
  • Prolonged use of a urinary catheter.
  • Vesicoureteral reflux, a condition that causes urine to flow the wrong way. In this condition, small amounts of urine flow from your bladder back up into your ureters and kidneys.


  • Permanent kidney damage: Permanent kidney damage can lead to chronic kidney disease.
  • Blood poisoning or Septicemia: Due to faulty filtration of blood through the kidneys.

9 Related Clinical Trials