Renal vein thrombosis (RVT) is a blood clot that develops in one or both of the renal veins. There are two renal veins — left and right — that are responsible for draining oxygen-depleted blood from the kidneys.

Renal vein thrombosis is not common and can cause serious damage to the kidneys and other life-threatening injuries. It occurs in adults more frequently than in children.

Symptoms of a small renal blood clot are minimal, if any. Some of the most common symptoms are:

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

Adolescent RVT symptoms

It’s very 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:

Blood clots often come on suddenly and don’t have a clear cause. There are certain factors that might make you more likely to develop these types of clots. Risk factors include:

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.

1. Urinalysis

A urine test called a urinalysis can be used to 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

Your 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 blood in the urine, masses or tumors, infections, kidney stones, and other abnormalities.

3. Doppler ultrasonography

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

4. Venography

Your doctor will take 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 will show in the imaging.

5. MRI or MRA

Magnetic resonance imaging (MRI) is a test using pulses of radio waves to produce images of organs and the internal structure of the body. It’s used 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 of the clot, including how big it is and whether there are clots in both renal veins. In some cases of small blood clots, your doctor may recommend you rest until your symptoms improve and the RVT goes away on its own.

Medication

The most common form of treatment is medication, which can 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. Thrombolytic medications can also be used to dissolve existing clots. Some of these drugs are distributed using a catheter inserted into the renal vein.

Dialysis

If the RVT has caused extensive kidney damage and renal failure, you may need to undergo dialysis temporarily. Dialysis is a treatment used to help return kidney functions to normal if they stop working efficiently.

Surgery

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

There’s no specific prevention method for this condition because it can be caused by a variety of conditions. One of the simplest things you can do is remain hydrated and drink water to reduce your risk of developing blood clots.

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