7 questions about kidney infections answered

An elderly woman was referred to me for recurring urinary tract infections (UTIs). She said to me “I just can’t get rid of these kidney infections!”

I asked her about her symptoms. Her’s was “pressure” in her pelvis. On further questioning, she said she would also have pain across her back when the infection “comes on.” She admitted that she never has fever or chills, and also no burning when she urinates, no blood in her urine, and no frequent, sudden urges to urinate. At baseline, she has urinary incontinence.

After evaluating the patient, my conclusion was that she was most likely not having kidney infections. I also strongly doubted that she was even having bladder infections, since she really did not have significant symptoms. The patient was surprised to hear that she was not having kidney infections, so I explained to her the features of kidney infections.

1 – How does a kidney infection arise?

A kidney infection, also known as pyelonephritis, occurs when germs invade the tissues of the kidney. Bacteria are the usual culprits; they ascend into the bladder from around the opening of the urethra (the tube that leads urine out of the bladder). The bacteria multiply in the bladder, then ascend up into the kidney, multiple again and invade the tissues of the kidney, causing infection. Less commonly, bacteria (or fungi) circulating in the blood stream, can lodge into a kidney and cause it to become infected.

2 – Who is more prone to kidney infections?

Kidney infections, like UTIs in general, are more common in women than men, because the urethra is shorter in women, therefore it is easier for bacteria to get into women’s bladders. Kidney infections are also more common in persons who have structural abnormalities of their urinary system, such as large cysts in the kidneys, and strictures (narrowing) of the ureter. The ureter is the tube leading from the kidney to the bladder.

Kidney stones also make a person more prone to kidney infections. A stone may get lodged in the ureter thereby blocking the passage of urine from the kidney to the bladder. That stagnant urine becomes infected and bacteria invade the kidney.

3 – What are the symptoms and signs of a kidney infections?

Classic symptoms are chills, fever, and flank pain. Some patients also experience nausea and vomiting, and I have had elderly patients who also experienced diarrhea. Sometimes patients also have the classic symptoms of a bladder infection as well (burning with urination, increased frequency of urination, and blood in the urine), but not all the time.

Related post: Why do I still have this UTI?

Going back to the flank pain – this is pain on one side of the back, just below the rib cage. It may initially be a nagging ache but may get progressively worst, becoming excruciating. Tapping or pressing on the flank of the affected side often elicits significant pain. Classically, the patient literally jumps when the area is tapped. Sometimes, even taking deep breaths in, causes the back pain to worsen.

So, the back pain of a kidney infection, is not your simple lower back ache, or pain. It is a more focal and associated with more generalized malaise.

4 – How is a kidney infection diagnosed?

Often the diagnosis is made after hearing the patient’s symptoms and examining them. To confirm, a sample of urine is tested for the presence of pus cells, and also cultured to identify bacteria. Sometimes, if there is doubt, an ultrasound is done, and this usually shows the swollen kidney. Occasionally, there is also an abscess present in the infected kidney.

5 – What is the treatment of a kidney infection?

The treatment of a kidney infection is antibiotics, given promptly. In some patients, the kidney infection is so severe, that they become septic, with low blood pressure, fast heart rate, rapid breathing, and high levels of white blood cells (WBCs) in their blood. Septic patients must always be admitted to hospital for intravenous (IV) antibiotics.

Other patients who should be admitted to hospital for IV antibiotics include those with kidney stones, elderly patients, persons with weak immune systems, and pregnant women.

6 – Can someone get a kidney infection more than once?

It is possible to get a kidney infection more than once. It is those persons who have structural abnormalities of their urinary system (mentioned above) who are prone to getting kidney infections more than once. If someone keeps getting kidney infections but was never diagnosed with a structural abnormality of their urinary system, they need to be evaluated for such. Often, a Urologist assists with such an evaluation.

7 – How can kidney infections be prevented?

Fixing structural abnormalities of the urinary tract is a big factor in preventing kidney infections. Because a kidney infection is often the result of extension of infection from the bladder, preventing bladder infections also contributes to the prevention of kidney infections.

Adequate hydration to ensure the urinary system is “flushed”regularly, medication to make the urine more acidic, estrogen replacement in elderly women, Lactobacillus probiotic supplements, and treating an enlarged prostate in men, may help prevent bladder infections.

Related post: Men get UTIs too

Take home points…
-UTI does not automatically mean kidney infection; in fact, most UTIs are simple bladder infections.
-Kidney infections are often associated with fever and generalized malaise. Patients with kidney infections tend to be outright sick.
-Backpain alone, without fever, malaise, and urinary symptoms, is usually not caused by a kidney infection.