Renal vein thrombosis

Alternative names
Clot in the renal vein; Occlusion - renal vein

Renal vein thrombosis is a blood clot that develops in the vein that drains the kidney.

Causes, incidence, and risk factors
Renal vein thrombosis is a fairly uncommon situation that may happen after trauma to the abdomen or back, or it may occur because of a tumor, stricture (scar formation), or other blockage of the vein. It may be associated with nephrotic syndrome.

In some children it occurs after severe dehydration, and is a more serious condition than in adults. Dehydration is the most common cause of renal vein thrombosis in infants.

Renal vein thrombosis should be suspected if symptoms develop after femoral vein cannulation (such as for an angiogram test).


  • Flank pain or low back pain, may be severe  
  • Urine, bloody  
  • Urine output, decreased

Signs and tests
An examination is often nonspecific. It may indicate nephrotic syndrome or other causes of renal vein thrombosis.

  • A urinalysis may show large quantities of protein in the urine, or red blood cells in urine.  
  • An abdominal x-ray, abdominal CT scan, abdominal MRI, or abdominal ultrasound may show occlusion of the renal vein.  
  • Venography (angiography) of the vena cava or renal vein may indicate renal vein thrombosis.

The treatment is focused on preventing new clot formations and reducing the risk of the clot traveling to other locations in the body (embolization). Anticoagulants may be given to prevent formation of new clots. Bedrest or limited activity may be recommended for a brief per

Expectations (prognosis)
Renal vein thrombosis usually resolves over time without permanent injury to the kidneys.


  • Acute renal failure (if thrombosis occurs in a dehydrated child)  
  • Embolization of the blood clot to the lungs (Pulmonary embolism)  
  • Formation of new blood clots

Calling your health care provider
Call your health care provider if symptoms indicating renal vein thrombosis may be present.

If you have experienced renal vein thrombosis, call your health care provider if decreased urine output, difficulty breathing, or other new symptoms develop.

There is no specific prevention for renal vein thrombosis. Maintaining fluids in the body to avoid dehydration may help to reduce its risk.

Johns Hopkins patient information

Last revised: December 5, 2012
by David A. Scott, M.D.

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