Kidney Infection

Kidney infection is the invasion of one or both kidneys by Pathogens, which cause injury to the affected area(s).  It is an infection that occurs within the kidneys, medically known as pyelonephritis (PI-low-nef-ri-tis).

Pathogens are toxins, organisms (such as bacteria, viruses and fungi) and other agents that cause disease. Primarily, however, infection of the kidneys is caused by bacteria.

An infection can occur almost anywhere in the urinary tract, if the conditions are conducive for it.  Infection of the urinary tract is referred to as urinary tract infection.  The focus of this article, however, is primarily on kidney infection (or infection that occurs within the kidneys).

How Can The Kidneys Become Infected?

Bacteria are the main cause of kidney infections.  These particular bacteria live in the colon and are called the Escherichia coli (E. coli) bacteria.  

How do these bacteria, which normally live in the colon, find their way to the kidneys?

There are two (2) main ways in which bacteria can enter the kidneys:

  1. The first is through blood that has been infected by bacteria. As the kidneys filter blood, removing excess water, salt and other nitrogenous wastes (such as uric acid and urea), bacteria present in the infected blood can get into the kidneys.

    If the bacteria remain long enough in the kidneys, they can infect them and cause inflammation and kidney damage.

  2. The second way by which bacteria usually enter the kidneys is through infected urine that is either stagnated (mainly due to blockage within the urinary tract), or urine that flows in the wrong direction (from the bladder to the kidneys - as is the case with kidney reflux disease).

    Urinary System

    If the E. coli bacteria get into the urethra it can find its way into the kidneys. Some common ways in which bacteria can get into the urethra are through sexual intercourse, wiping from back to front (especially females), waiting too long to urinate (causes urine stagnation), and external objects such as diaphragms (for birth control). Women, in particular, are susceptible to infections via these channels.

    If these bacteria remain long enough in the urethra and are allowed to multiply, they can move up into the bladder then into the ureters and eventually into the kidneys. This is especially likely to happen if urine flows backward, in the wrong direction.

It should be noted that while bacterial infection is the primary cause of pyelonephritis (infection of the kidneys); there are other causes of kidney infection.

How Can You Know if You Have Kidney Infection?

Kidney Infection

The symptoms of kidney infection are usually very noticeable and can be rather severe.   In some cases, the onset of symptoms can be quite sudden (acute), especially if infection is caused by bacteria in the blood.

When infection begins in other areas of the urinary tract (excluding the kidneys) the initial symptoms may be mild and, in some cases, hardly noticeable.

It is important, however, not to ignore early warning signs of urinary tract infection (UTI).  Recognition of these early warning signs is important since it can help to expedite the diagnosis and treatment of UTI, before the infection spreads to the kidneys.

Kidney infection is a serious condition and requires prompt treatment in order to minimize damage to the kidneys.  If the condition is allowed to persist, kidney damage can be severe leading to kidney impairment and, eventually, kidney failure.

Early symptoms may include the following:

  • The urge to urinate frequently;
  • Passing only small amounts of urine, despite the frequent urge to urinate;
  • Pain or burning in the bladder or urethra during urination;
  • Uncomfortable pressure or pain around the pubic area;
  • Cloudy or milky-looking urine.

When the kidneys become infected, the symptoms are much more severe and, in addition to the symptoms listed above, may also include the following:

  • Fever;
  • Severe pain in the lower back or sides (below the ribs);
  • Vomiting and nausea;
  • Headaches;
  • Feeling tired and weak.

Remember, effective, early treatment is essential to avoid or minimize kidney damage.  So pay attention to any early symptoms of UTI.  If you suspect that you may have a urinary tract infection, visit your doctor without delay.

How is Kidney Infection Treated?

Treatment is most effective when the condition is caught early.  If the infection is detected within the urinary tract, and has not reached the kidneys, treatment is fairly standard. Once there are no other complications, the standard treatment is antibacterial drugs.

Kidney Infection Treatment

The length of treatment depends on the severity of the infection.  Mild infections can be cured in a couple of days but some doctors may prescribe antibiotics for a week or two, as a precaution, to ensure that the infection is totally gone.

More severe infections may take weeks before they are completely cured.

When there is infection of the kidneys themselves (pyelonephritis), prompt treatment is essential.  Untreated kidney infection can quickly lead to kidney damage and other complications.

Severe infection of the kidneys can take many weeks of antibiotic treatment before it is completely cured.  In some cases, if the patient becomes too weak, it may be necessary for them to be hospitalized until they are strong enough to take medication on their own.  Intravenous (IV) fluids and other medication may also be required, to help the patient recover.

It is important for patients to complete their course of treatment, even if symptoms disappear before the medication is finished.  Sometimes, symptoms may disappear before the infection is completely cured, but premature discontinuation of treatment could result in re-occurrence of the infection.

How do You Prevent Kidney Infection?

There are measures that can be taken to minimize urinary tract infection and, by extension, infection of the kidneys.  These measures are not absolutely preventative but they can minimize the risk.

These include the following:

  • Drink adequate amounts of water every day.  This helps to flush out the urinary system continuously and avoid any buildup of bacteria in the urinary tract.
  • Don't hold in urine for long periods.  You should urinate when you feel the need to.  This will minimize the risk of bacterial buildup and help to prevent them from moving up (backwards) in the urinary tract.
  • If you can, try to urinate after sexual intercourse.  Again this will help to flush out any bacteria, which may have been exchanged during intercourse.
  • Wipe from front-to-back after a bowel movement or passing urine (especially important for women... as this will minimize the risk of bacteria spreading from the anus to the vagina).
  • Persons who are particularly susceptible to urinary tract infections should consider using cotton underwear, since it is breathable and may prevent bacterial growth near the urethra.

Even after taking these precautions, one can still be affected by infection of the kidneys or urinary tract.  Infected blood, for instance, can cause kidney infection.  Additionally, any blockage within the urinary tract or any deficiencies, which cause urine to flow in the wrong direction, increase the risk of kidney infection. If you experience any of the symptoms outlined earlier, do not hesitate to visit your doctor.

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