Diagnosing and Treating Hydronephrosis

Treatment options for hydronephrosis, a common form of obstructive nephropathy

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Hydronephrosis implies a condition where the kidneys or the urinary tract become swollen and enlarged due to too much urine buildup. The condition can affect either one or both kidneys. The basics of hydronephrosis are covered here.  This article is limited to its diagnosis and treatment.


If someone has the telltale symptoms of hydronephrosis, the following tests might help in confirming the diagnosis:

  • The typical blood test to assess kidney function might be helpful.  At the very least they will indicate problems with the kidneys.  However they might not be enough to confirm the reason for the drop in kidney function.  Therefore blood and urine tests are nonspecific and will usually lead to further investigations.
  • Imaging tests are more specific and can confirm the diagnosis.  These include tests like kidney ultrasound, CT scans of the kidney, and another test that we now do less often called intravenous urography.


Treatment of hydronephrosis depends on the cause which led to the hydronephrosis. Many situations will require surgical intervention for severe cases, especially when they developed suddenly. For instance, an obstructing stone that has led to sudden kidney failure.

The foremost treatment priority is to "decompress" the urinary system, and preferably relieve any obstruction that is causing the hydronephrosis.

The goal is to prevent permanent damage to the kidney which otherwise could ensue quickly.  In that case dialysis or kidney transplantation might become necessary.  Therefore, timely surgical intervention might be necessary before one gets to the point of no return.

Another situation where quick surgical intervention is necessary is when the obstruction in the urinary tract is present in combination with infection of the urinary tract or the blood.

 Obstruction plus infection usually calls for urgent surgery.

Since damage to the kidneys in hydronephrosis occurs from high urine pressure in the kidneys, the first intervention will often involve relieving this pressure by letting the urine drain out.  If the obstruction is downstream, a simple measures like insertion of a Foley catheter into the bladder might be all that it takes to do this.  However for more upstream obstructions, like in the ureter, a tube  might need to be inserted directly into the kidney through an incision in the skin (called a nephrostomy).  This then forms an alternative upstream channel for the urine to be drained out.  The resulting relief in pressure that is obtained often buys the patient valuable time until the specific cause can be fixed.


Once The urinary system has been decompressed, the physician can focus his attention towards fixing the actual cause that led to the problem.  Here are a few examples of what might be required:

  • Cancerous masses can either be removed or treated with radiation, chemotherapy, or all of the above
  • Obstructing kidney stones can either be removed or broken up using sound waves or lasers (lithotripsy)
  • Ureteral strictures might he relieved by putting stents in the ureter
  • Prostatic enlargements might respond to medications or surgical procedures like TURP
  • Antenatal hydronephrosis is a special situation and its treatment is covered elsewhere


Hydronephrosis is a common finding in pregnancy.  Most physicians will elect to take a "wait and watch" approach- or observe and keep an eye on it while testing the kidney function using blood tests. However if the obstruction is severe to the point where permanent damage to the kidney is inevitable, interventions requiring ways to decompress the urinary system might still be necessary.


Sometimes, dilatation of the ureter tract might be interpreted as hydronephrosis.  However, dilatation is not always equivalent to obstruction.  Some patients might just have a physiological dilated urinary tract that looks different from the accepted "normal".  Cysts in the kidney can often mimic hydronephrosis.  The situations, as can some mild cases of hydronephrosis, might just be observed rather than require surgical intervention.

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