Kidney Infection: Symptoms, Causes, Treatment

A kidney infection (pyelonephritis) is a painful and unpleasant illness caused by bacteria travelling from your bladder into one or both of your kidneys.It's more serious than cystitis , a common infection of the bladder that makes urinating painfulادرار. If treated promptly, a kidney infection doesn't cause serious harm, but will make you feel very unwell. If a kidney infection isn't treated, it can get worse and cause permanent kidney damage .Symptoms of a kidney infection often come on within a few hours. You can feel feverish, shivery, sick and have a pain in your back or side .

See doctor if you have a fever and persistent tummy, lower back or genital pain, or if you notice a change to your usual pattern of urination.Most kidney infections need prompt treatment with antibiotics to stop the infection from damaging the kidneys or spreading to the bloodstream. You may also need painkillers.In rare cases, a kidney infection can cause further problems include blood poisoning (sepsis) and a build-up of pus in the kidney called an abscess.

What is a kidney infection?

When a kidney becomes infected, the condition is medically referred to as pyelonephritis. kidney infection is only one of several types of infections encompassed by the term UTI. The spectrum of UTIs includes:

• Acute uncomplicated cystitis (bladder infection)
• Recurrent cystitis
• Complicated UTI
• Prostatitis (prostate infection)
• Kidney infection (pyelonephritis)
• Catheter-associated UTI (in individuals with indwelling urinary catheters)
A more general classification of urinary tract infection is the following:
• Lower urinary tract infection involves the urethra, the bladder, and, in men, the prostate gland.
• Upper urinary tract infection refers to infection of the kidneys.

Causes and risk factors of kidney infection?

Typically, bacteria gain access to the urinary system from outside through the urethra (the drainage tube for urine from the bladder). The bacteria may then ascend in the urinary system and cause kidney infections. Kidney infection (upper UTI) is typically more severe than lower UTI because bacteria may also infect the bloodstream (bacteremia) from the kidneys resulting in a more severe illness.

There are many factors that may increase the chances for infection of the kidneys and urinary tract.
 Premenopausal women are at higher risk for developing UTI and kidney infection. Risk factors within this population include:
• Sexual intercourse
• Previous urinary tract infection
• Use of spermicides
• History of mother with recurrent UTIs (which suggests a possible genetic component to susceptibility)

 some pregnant women may have urinary infections during their pregnancy. This may occur because of slower transit of urine in the ureters during pregnancy from the pressure applied by the enlarging uterus

 In post-menopausal women, physiological factors (vaginal dryness, urinary incontinence, urinary retentionاحتباس ,
and prolapse of the pelvic organs seem to add potential risk to develop UTIs and kidney infections.

 In men, prostate enlargement is the main risk factor for UTI and kidney infectio.

 Urinary catheters (Foley catheters) also increase the risk of developing urinary and kidney infections. These catheters are used in settings where an individual may not be able to urinate due to paralysis (neurogenic bladder), prostate enlargement (BPH), prostate cancer, severe illness, bed bound state, incontinence of urine (inability to hold their urine), or bladder dysfunction. Urinary catheters simply provide a physical vehicle for the bacteria from outside to be directly transported into the bladder and the urinary system.

 Kidney stones کلیه and structural abnormalities of the urinary system may also cause kidney infection. Impaired draining and blockage of urine(urinary retention) may cause bacteria to ascend to the kidney without being washed back down with the urine. Any obstruction to the flow of urine can serve as a focus of infection that can spread to other parts of the urinary tract.

 Urinary stents placed in ureters to relieve obstruction due to stones or tumors are also a potential risk for kidney infection. As matter of fact, any instrumentation or procedure of the urinary system stenting, cystoscopy , biopsy, and transurethral resection of the prostate (TURP) can pose a risk for infection of the urinary tract.

 Diabetes may also increase the risk of kidney infection in both men and women. Other conditions or medications that suppress immune function increase the risk of kidney infection.

 In children, risk factors for kidney infection include female gender, uncircumcised male, structural abnormalities of the urinary tract, and Caucasian race.

signs and symptoms

Some of the common symptoms of kidney infection include:
• fever,
• nausea,
• vomiting,
• abdominal pain,
• shivering,
• shaking -- chills,
• painful urination (dysuria)
• frequent urination (urinary frequency)
• urge to urinate (urinary urgency)
• flank and low and mid back pain (dull kidney pain), and
• generalized malaise.
Signs of kidney infection on exam may include:
• fever,
• tenderness on the flanks and
• clinical evidence of infection in the urinalysis (laboratory analysis of urine).

In elderly patients and those with weak immune systems, kidney infection may be more severe with confusion, lethargy, rapid heart rate, low blood pressure, and dehydration.

How is kidney infection diagnosed?

Kidney infection may be diagnosed by a physician by performing a complete physical examination and taking a detailed medical history. The evaluation includes checking the vital signs, assessing for signs of dehydration, and checking for tenderness on the mid and lower back. In young, female patients a pelvic exam may also be necessary to evaluate for pelvic infection.

Urinalysis test is essential for the diagnosis of kidney infection. The urine sample must be properly collected. The urethra needs to be wiped clean properly before the sample is collected in order to avoid contamination of urine by the bacteria on the skin around the urethra. The initial stream of urine is preferably voided in the toilet before the collecting urine in the provided container. This is called the mid-stream, clean-catch urine. After an appropriate amount of urine is collected (about 10 milliliters or cc's) in the container, the remaining urine may also be voided in toilet.

A urinalysis suggestive of an infection in the urine (presence of white blood cells or bacteria in the urine) in general, is highly suggestive and supportive of the diagnosis of kidney infection or urinary tract infection.
Once white blood cells and other indications of urine infection (such as, leukocyte esterase [produced by white blood cells in urine] or nitrites [produced by bacteria in urine]) are noted on the urinalysis, it is important to determine the amount and the type of bacteria in the urine sample.

What is the treatment for kidney infection?

The most important component of treating kidney infection (as with any bacterial infection) is timely initiation of antibiotics under the directions of doctor. If kidney infection is diagnosed, then an empiric antibiotic (an antibiotic that would cover all likely causative bacterial organisms) is usually prescribed. A urine and blood sample will be taken and sent to a laboratory for analysis of any bacterial growth (urine culture and blood culture).

When a specific type of bacteria is isolated, antibiotics may then be changed to those that are more active against that particular bacterial type. If the bacteria shows resistance (unresponsive) to the antibiotic that was initially prescribed, then the antibiotic is changed promptly to one that the organism is susceptible to in order to cure the kidney infection.

Home treatment with oral antibiotics and adequate water and fluid intake are usually effective for curing uncomplicated kidney infection and urinary tract infection. Nondrug home treatment with fluid intake, cranberry products, or acupuncture without antibiotics is not advisable for kidney infections.

However, if symptoms are severe (uncontrolled nausea and vomiting resulting in inability to take medications) or the infection is difficult to control with the routine oral medications for kidney infection, then hospitalization may be required to receive intravenous antibiotics, intravenous hydration, and aggressive management of symptoms. In cases of complicated kidney infection hospitalization may also be necessary.

Self-medication for kidney infection is considered only in patients with mild, recurrent urinary infections. In individuals who are reliable and familiar with the symptoms of kidney infection, appropriate antibiotics prescribed to them in advance by their treating physicians may be started at the onset of their symptoms.