Renal vein thrombosis (RVT) is a serious condition in which a blood clot forms in one or both of the veins that filter blood from the kidneys.

Renal vein thrombosis (RVT) occurs when a blood clot develops in one or both of the renal veins. RVT is a rare form of deep vein thrombosis (DVT), a serious condition where a blood clot develops in a major vein in the body.

Two renal veins — left and right — are responsible for draining oxygen-depleted blood from the kidneys. A lot in one or both of the veins can affect your kidney function.

Renal vein thrombosis is a serious condition. It can cause damage to the kidneys, including kidney failure, and be life threatening. It occurs in adults more frequently than in children.

It typically occurs due to another condition affecting the kidneys, such as nephrotic syndrome, kidney disease, or kidney tumors.

Keep reading to learn the symptoms, risk factors, and treatment options for RVT.

A small renal blood clot may occur without symptoms. RVT may also look different depending on the underlying cause.

Symptoms can include:

A blood clot that travels to the lung can occur in more severe cases. If a piece of the renal vein thrombosis breaks off and travels to your lungs, it can cause chest pain that worsens with every breath.

RVT symptoms in children

It’s rare for children to get RVT, but it can happen. Cases of adolescent RVT cause more sudden symptoms. First, they may experience back pain and discomfort behind the lower ribs. Other symptoms may include:

  • pain in the hips
  • decreased urine
  • bloody urine
  • fever
  • nausea
  • vomiting

In infants, it may occur with symptoms that include:

  • blood in urine
  • flank mass
  • signs of dehydration, such as crying without tears and cold hands or feet
  • shock
  • decreased or no urine output

Blood clots often come on suddenly and don’t have a clear cause. Certain factors might make you more likely to develop these types of clots. Causes can include:

  • dehydration, especially in the rare case of RVT in infants
  • tumors affecting the kidneys
  • trauma or injury to the back or abdomen
  • kidney disease
  • kidney transplant

Other medical conditions are also associated with renal vein thrombosis, including hereditary blood clotting disorders.

Nephrotic syndrome, a kidney disorder causing the body to release an excess of protein in the urine, can lead to RVT in adults. It’s typically a result of excessive damage to blood vessels in the kidneys.

Doctors perform multiple tests to diagnose renal vein thrombosis and any underlying conditions that may contribute to it.

1. Urinalysis

A urine test called a urinalysis can help doctors identify the underlying cause of RVT and detect kidney issues. If your urinalysis shows excess protein in the urine or an irregular presence of red blood cells, you could possibly have RVT.

2. CT scan

A doctor may use this noninvasive imaging test to take clear and detailed images of the inside of your abdomen. CT scans can help to detect swelling, masses or tumors, infections, kidney stones, and other abnormalities.

3. Doppler ultrasonography

This form of ultrasound imaging can produce images of blood flow. This can ultimately help to detect irregular blood circulation to the renal vein.

4. Venography

A doctor may order X-rays of the kidney veins in a venography. This involves using a catheter to inject a special dye into the veins. The doctor will use the X-ray to see how the dyed blood flows. If there’s a blood clot or blockage, it typically shows in the imaging.

5. MRI or MRA

Magnetic resonance imaging (MRI) is a test that uses pulses of radio waves to produce images of organs and the internal structure of the body. Doctors use it primarily to detect tumors, internal bleeding, infections, and arterial issues.

A magnetic resonance angiogram (MRA), on the other hand, is used to see the inside of your blood vessels and veins. This test can help to identify and diagnose blood clots and check for aneurysms.

Treatment for RVT depends on the severity. This can include its size and whether there are clots in both renal veins. In some cases of small blood clots, a doctor may recommend rest and medication until your symptoms improve.

Medication

Doctors typically prescribe medication to dissolve clots or prevent them from forming. Blood thinners (anticoagulants) are designed to prevent blood clots and may be the most effective way of preventing new clots. Doctors also prescribe thrombolytic medications to dissolve existing clots. They may use a catheter to distribute these medications directly into the renal vein.

Dialysis

If the RVT has caused extensive kidney damage and renal failure, you may need to temporarily undergo dialysis. Dialysis performs the kidney functions of filtering your blood to remove excess waste.

Surgery

If your RVT becomes severe, you may need surgery to remove clots from the renal vein. In rare instances, and only if there are complications, you may need to have a kidney removed.

Typically, doctors can successfully treat RVT by prescribing medication to break up the blood clot and prevent future clots from forming.

But the underlying cause of RVT and how well your kidneys function can affect your prognosis. You may require additional treatment for kidney disease or another condition.

There’s no specific prevention method for this condition because various conditions can cause it.

Staying hydrated by drinking water may help reduce your risk of developing blood clots by preventing dehydration.

If you have a blood clotting disorder and already take blood thinners, maintaining your treatment plan can also prevent RVT. Deviating from a prescribed treatment plan can increase the risk of complications.

RVT occurs when a blood clot forms in one or both of the renal veins. It can be serious and affect your kidney function.

It typically results from another condition affecting the kidneys.

Doctors typically treat the underlying cause and prescribe medication to reduce and prevent blood clotting.