Blockage of the Renal Arteries

The renal arteries are blood vessels that carry blood to your kidneys. A blockage means the renal arteries become narrowed or clogged so blood can't get through.

• Kidney arteries can be blocked gradually by narrowing or suddenly by a blood clot

• A sudden block in the renal arteries causes an aching pain in your lower back or belly, a fever, and nausea

• Blockage can lead to high blood pressure or kidney failure

• Doctors treat a block in the renal arteries with medicine and surgery

Your renal arteries can be blocked when:

• A clot from somewhere else in your body is carried by your blood to one or both of your kidneys

• A blood clot forms in your renal artery

• Hardening of your arteries (atherosclerosis) or other health problems can make the walls of your renal artery thick, stiff, and narrow

A blood clot usually affects only one kidney. Narrowing of the arteries usually affects both kidneys.

A sudden, complete blockage may cause:

• Aching pain in your lower back or lower belly

• Fever

• Feeling sick to your stomach and throwing up

Sudden, complete blockage usually affects only one kidney. Usually your other kidney takes over the work of filtering your blood and making urine and you don't get kidney failure.

A partial blockage doesn't usually cause symptoms, but it may give you:

• High blood pressure

Partial blockage usually affects both kidneys. If it goes on long enough, you may get kidney failure.

Doctors suspect a blockage from your symptoms. They may do imaging tests of the urinary tract:

• Computed tomography angiography (a type of CT scan that focuses on your blood vessels), magnetic resonance angiography (a type of MRI that focuses on your blood vessels), or ultrasound

• Sometimes, conventional angiography (injecting a special liquid called a contrast agent into your blood vessel, allowing doctors to see your blood vessels on an x-ray)

They'll also do blood and urine tests to see how well your kidneys are working.

Doctors do different treatments depending on what caused the blockage:

• Blood clots: Blood thinners (anticoagulants) to prevent clots from getting bigger and new clots from forming

• Narrowed arteries: Surgery or angioplasty to open the artery

During angioplasty, doctors guide a thin tube through your groin to your blocked artery so they can widen it using a tiny balloon or a small wire tube called a stent.

If the blockage caused high blood pressure, doctors will give you high blood pressure medicine.

If you have kidney failure, you may need dialysis (a machine filters your blood when your kidneys aren’t able to do it).