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Kidney Reflux Disease

Kidney Reflux Disease

Kidney reflux disease (vesicoureteral reflux) is found mainly in children who inherited it from their parents.  It can also be caused by infections or blockage anywhere in the urinary system.


Actually, this condition does not really originate in the kidneys.  It begins in the bladder and, over time, can eventually affect the kidneys.  It is characterized by the flow of urine in the wrong direction.

Typically, after urine is produced by the kidneys it is transported through two tubes, which connects the kidneys to the bladder, called ureters and then it flows into the bladder.  It is stored in the bladder before being expelled from the body, by a familiar process known as urination.

With vesicoureteral reflux, urine tends to flow in the opposite direction.

What is Kidney Reflux Disease?

Urination is episodic... meaning that it occurs when we allow it. It is the voluntary relaxation of a muscle called the sphincter, which is a circular muscle located between the opening of the bladder and the urethra.

There are three distinct actions that occur during the urination process:

  1. The bladder muscle contracts;

  2. The valves at the openings between the ureters and the bladder are normally squeezed shut, and

  3. The sphincter muscle relaxes, allowing urine to flow from the bladder through the urethra. These three simultaneous actions force the urine to exit through the urethra and also prevent urine from going back into the kidneys.


With kidney reflux disease, however, the connection between the ureters and the bladder malfunctions. So when the bladder contracts during urination, the openings from the ureters into the bladder do not squeeze shut. This allows urine to flow in the wrong direction, back up toward the kidneys, when the bladder muscle contracts. Medically, this condition is known as vesicoureteral reflux (VUR), commonly referred to as kidney reflux.


VUR can be classified as either primary or secondary.

Primary VUR occurs when a child is born with the condition. At birth, the valves located at the points where the ureters join the bladder are defective. These valves do not close properly, allowing urine to flow back up from the bladder, through the ureters and eventually to the kidneys. This condition tends to get better or disappear as the child gets older.

Typically, secondary VUR occurs when there is blockage in the urinary system, which causes urine to flow back into the kidneys.

Health Risks

Kidney reflux (vesicoureteral reflux) can cause serious health problems for patients.  When urine is forced back through the ureters and upwards into the kidneys, it puts pressure on the kidneys.  Over time, this pressure can damage both the ureters and the kidneys, causing them to dilate (become wider) and eventually lead to impaired kidney function.

Additionally, the urine that goes backwards into the ureters can quickly return to the bladder. Consequently, any bacteria which may have been in that urine re-enters the bladder and can cause infection.  The complete emptying of the bladder is a major defense against infection.  Children with kidney reflux disease are likely to get bladder infections more easily.

If the bladder becomes infected it is possible for the urine that goes backward to carry the infection (found in the bladder) up to the kidneys.  This can result in serious kidney diseases such as pyelonephritis (inflammation of the kidney).  This condition is caused by bacterial infection and can result in extensive kidney damage.


The damage done by kidney reflux is often undetected (especially in the early stages). One of the first indications of this disease is urinary tract infection.  A medical professional would usually check for the disease after a urinary tract infection.

Other symptoms could include:

  • high blood pressure;

  • bedwetting;

  • poor growth;

  • protein in the urine, and

  • kidney failure.


Kidney reflux disease is classified into five stages... grades 1 to 5.  Most children with grades I and II, are completely healed of the disease as they grow. The disease normally heals on its own, by the time the child reaches the age of 6 or 7 years.  Such spontaneous resolution of this disease is less common in children with grade III to grade V.

The great majority of children with vesicoureteral reflux outgrow this condition, over the course of several years. If infection occurs it could seriously affect the kidneys and bladder.  Treatment would normally involve antibiotics, in order to prevent or cure infections.  The use of antibiotics usually corrects secondary reflux, caused by infection.  Sometimes surgery is necessary to correct primary reflux.

Treatment of kidney reflux disease attempts to prevent or minimize kidney damage.  The type of treatment depends on the age of the child and the nature or cause of the reflux.

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