The clot can damage the kidney.
Symptoms may be minimal unless the clot develops suddenly.
Diagnosis is with magnetic resonance angiography, Doppler ultrasonography, or computed tomography angiography.
Treatment may include anticoagulant drugs, clot-dissolving (fibrinolytic) drugs, and removal of the clot.
(See also Overview of Blood Vessel Disorders of the Kidneys Overview of Blood Vessel Disorders of the Kidneys The blood flow to the kidneys needs to be intact for the kidneys to function properly. Any interruption of or reduction in the blood flow can cause kidney damage or dysfunction and, if long-standing... read more .)
Causes of Renal Vein Thrombosis
In adults, the most common cause of renal vein thrombosis is
In nephrotic syndrome, large amounts of protein are lost in the urine and the blood has an increased tendency to form clots.
Renal vein thrombosis may also be caused by kidney cancer or conditions that put pressure on the renal vein (for example, a tumor) or on the inferior vena cava, into which the renal vein drains. Other possible causes are blood clotting disorders (hypercoagulability disorders), vasculitis Overview of Vasculitis Vasculitic disorders are caused by inflammation of the blood vessels (vasculitis). Vasculitis can be triggered by certain infections or drugs or can occur for unknown reasons. People may have... read more , systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more (lupus), sickle cell disease Sickle Cell Disease Sickle cell disease is an inherited genetic abnormality of hemoglobin (the oxygen-carrying protein found in red blood cells) characterized by sickle (crescent)-shaped red blood cells and chronic... read more or diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more that affects the kidneys, oral contraceptive use, injury, cocaine abuse, or, rarely, thrombophlebitis migrans—a condition in which clotting occurs sequentially in different veins all over the body.
Symptoms of Renal Vein Thrombosis
Renal vein thrombosis occurs most often in adults. In adults, onset and progression are usually gradual and without symptoms. An occasional clue to doctors is when a piece of clot breaks off and travels from the renal vein to the lungs (pulmonary embolism Pulmonary Embolism (PE) Pulmonary embolism is the blocking of an artery of the lung (pulmonary artery) by a collection of solid material brought through the bloodstream (embolus)—usually a blood clot (thrombus) or... read more ). This event causes sudden pain in the chest that is made worse by breathing, along with shortness of breath. In other people, urine production diminishes.
In most children and a limited number of adults, onset and progression are usually sudden. Pain, often the first symptom, typically occurs in the back behind the lower ribs and in the hips. The person may have fever, nausea, vomiting, less than a normal amount of urine, and blood in the urine.
Diagnosis of Renal Vein Thrombosis
Blood and urine tests
Blood tests may indicate evidence of a decrease in the ability of the kidneys to process and excrete the body's waste products (kidney failure) Overview of Kidney Failure This chapter includes a new section on COVID-19 and acute kidney injury (AKI). Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney... read more . Routine urine testing is also done.
Magnetic resonance (MR) angiography Magnetic resonance angiography (MRA) In magnetic resonance imaging (MRI), a strong magnetic field and very high frequency radio waves are used to produce highly detailed images. MRI does not use x-rays and is usually very safe... read more , Doppler ultrasonography, and computed tomography (CT) angiography are the tests doctors use to diagnose renal vein thrombosis (see Imaging Tests of the Urinary Tract Imaging Tests of the Urinary Tract There are a variety of tests that can be used in the evaluation of a suspected kidney or urinary tract disorder. (See also Overview of the Urinary Tract.) X-rays are usually not helpful in evaluating... read more ). MR angiography and CT angiography are highly accurate and do not require insertion of a catheter into an artery or a vein deep in the body. Ultrasonography is not as accurate, but it is very safe. Ultrasonography shows enlarged kidneys if the blockage developed suddenly. Doppler ultrasonography may show that there is no blood flowing in the renal vein. X-rays of the inferior vena cava or the renal vein that are taken after a radiopaque contrast agent is injected into an artery or deep vein (venography) is the most accurate test but may cause clots to break off and travel through the bloodstream, becoming emboli, which can cause complications.
Treatment of Renal Vein Thrombosis
Treatment of the underlying disorder
Drugs that prevent or dissolve blood clots
The underlying disorder is treated. The primary treatment is with anticoagulant drugs, which usually improve kidney function by preventing the formation of additional clots and reducing the risk of pulmonary embolism Pulmonary Embolism (PE) Pulmonary embolism is the blocking of an artery of the lung (pulmonary artery) by a collection of solid material brought through the bloodstream (embolus)—usually a blood clot (thrombus) or... read more . Sometimes a catheter is inserted into the vein to give a drug that dissolves clots (fibrinolytic) or to remove the clot (called thrombectomy). These newer treatments are becoming more widespread but are still not routine. Rarely, surgery is done to remove clots in the renal vein. A kidney is rarely removed and then only if other complications, such as high blood pressure High Blood Pressure High blood pressure (hypertension) is persistently high pressure in the arteries. Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying... read more , develop.
The outcome depends on the cause of the thrombosis, complications, and the degree of kidney damage. Death from renal vein thrombosis is rare and usually results from a fatal underlying disorder or from complications, such as a pulmonary embolism. The effects on kidney function depend on whether one or both kidneys are affected, whether blood flow is restored, and what the state of kidney function was before the blockage occurred.
The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
American Association of Kidney Patients (AAKP): AAKP improves the lives of patients through education, advocacy, and promotion of a sense of community among patients with kidney disease.
American Kidney Fund (AKF): AKF provides information about kidney disease and kidney transplant, needs-based financial assistance to help manage medical expenses, webinars for medical professionals, and opportunities for advocacy.
National Kidney Foundation (NKF): This clearinghouse provides everything from information on the basics of kidney function to access to treatment and support for people with kidney disease, continuing medical education courses, and research opportunities and grant support for medical professionals.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): General information on kidney diseases, including research discoveries, statistics, and community health and outreach programs.