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Hydronephrosis, or swollen kidneys, is a urological condition where the kidney urinary collecting system is dilated. Hydronephrosis is not a disease in and of itself, but it can be caused by conditions that affect the kidney and the urinary tract.

If hydronephrosis is left untreated, the pressure of the built-up urine, which normally flows through the urinary tract, may cause pain, swelling, and permanent damage to the kidneys. Untreated hydronephrosis can lead to permanent loss of kidney function – a life-threatening condition – so if you experience its symptoms, seek prompt medical attention.

Hydronephrosis may involve one or both kidneys. It is related to hydroureter, or swelling of the ureter, and often coincides with or causes this condition.

Symptoms of Hydronephrosis

The symptoms of hydronephrosis depend on how long you have had the obstruction, but will probably include some or all of the following:

  • Tenderness or pain in abdomen or side
  • Fever
  • Nausea and vomiting
  • For women, one of the most common symptoms of a swollen kidney or hydronephrosis is a urinary tract infection, or UTI. Common symptoms of a UTI, in addition to frequent and painful urination mentioned above, would also include:
  • Back pain
  • Fever
  • Cloudy urine
  • Blood in urine

Hydronephrosis and urinary tract infections are potentially very serious conditions that can lead to other complications. If you experience symptoms, contact your doctor promptly.

Causes of Hydronephrosis

A common cause of hydronephrosis is the blockage of the ureter, the tube that connects the kidney to the bladder. The blockage is most often caused by a kidney stone, but may also be caused by scarring or blood clots. The blockage, regardless of the underlying cause, results in the urine not being able to drain out of the kidney, causing it to build up.

Other common causes of hydronephrosis include:

  • Tumors close to or in the ureter
  • Congenital narrowing of the ureter
  • Injury to the kidney or ureter, especially one affecting the ureteropelvic junction (UPJ), which connects the ureter to the kidney
  • Blockage of the bladder

Diagnosing Hydronephrosis

Early diagnosis of hydronephrosis is crucial to prevent permanent kidney damage. Diagnostic testing to detect hydronephrosis is usually performed with ultrasound, a painless procedure that can detect swelling in the kidney. Also helpful are CT scans, which can provide a visual image of the affected organ and urinary tract.

A nuclear renal scan, which allows the doctor to gauge the amount of obstruction, may also be performed. In this procedure, an injection of a nuclear isotope is given. A specialized camera outside the body tracks the isotope through the kidneys and bladder in order to determine the function of the kidney and the flow of urine.

Treatment for Hydronephrosis

Treatment for hydronephrosis focuses on removing whatever is causing the obstruction, so that urine can flow freely again and the kidneys can achieve maximum function. Treatments may include:

  • Ureteral stent opening up the ureter passageway to allow free flow of urine
  • Nephrostomy tube that creates an alternate path for urine drainage
  • Antibiotics for infection control
  • Removal of scar tissue, kidney stone, or blood clot through endoscopic surgery

Miami urologist Dr. Marvin Bondhus diagnoses and treats hydronephrosis in our South Miami office. For a consultation, call (305) 661-9692 or request an appointment online.