Renal artery stenosis is a slimming of one or more arteries that provide blood to the kidneys. The reduction of arteries limits the regular flow of O2 rich blood to your kidneys. 

For the filtration of waste materials and eliminating extra fluids, your kidneys require enough blood flow. Reduced blood flow to the renal can induce tissue damage and elevate blood pressure throughout the system.

Symptoms of Renal Artery Stenosis:

  • Renal artery stenosis usually has no symptoms or indications until it is severe. The issue may be detected by chance when checking for anything else. Your doctor may detect an issue if you have any of the symptoms associated:
  • High blood pressure that appears out of nowhere or develops without a warning
  • Hypertension develops before the age of 30 or after the age of 50.

Additional indications and symptoms of renal artery stenosis include:

  • Hypertension is difficult to manage.
  • Your doctor hears a whooshing sensation with a stethoscope placed over your kidneys as blood rushes through a constricted artery (bruit).
  • Protein amounts in the urine that are abnormally high or other symptoms of impaired kidney functioning.
  • Following therapy for hypertension, renal function deteriorates.
  • Inflammation is the body’s tissues due to fluid excess.
  • Heart failure that is unresponsive to treatment.


Two main factors cause renal artery stenosis:

1. Inflammation of the kidney (renal) arteries –  Plaque (fats, cholesterol, and other chemicals) can start building up in and on the walls of your renal arteries (atherosclerosis). 

These deposits can solidify, reducing blood flow, causing kidney scarring, and eventually narrowing the artery as they become bigger. 

The most frequently observed cause of renal artery stenosis is atherosclerosis, affecting any part of the body.

2. Fibromuscular dysplasia – The muscle in the arterial wall grows improperly in fibromuscular dysplasia, which usually begins in childhood. The renal artery can contain thin sections that alternate with broader sections, giving visuals of the artery a bead-like texture. 

The renal artery can clog to the point where the kidneys don’t get enough blood, resulting in hypertension at an early age. One or both kidneys may be impacted. 

Experts aren’t sure what causes fibromuscular dysplasia, although it’s more frequent in women and could even be present at birth (congenital). 

Renal artery constriction and fibromuscular dysplasia can affect your kidney arteries and other arteries in your system.

3. Renal artery stenosis can also be caused by other illnesses such as blood vessel inflammation or a tumor that forms in your belly and presses on your kidneys’ arteries.

Risk Factors:

Constricted kidney arteries are the most causative agent of renal artery stenosis. The following are risk factors for constricted arteries in your kidneys and other parts of your body:

  • Aging
  • Hypertension 
  • Obesity Diabetes High cholesterol
  • Tobacco usage
  • Lack of physical activity


Your doctor may start with the following tests to diagnose renal artery stenosis:

  • A physical exam in which your doctor listens over the kidney areas using a stethoscope for sounds that could indicate a constricted artery to your kidney.
  • A review of your medical records.
  • Kidney function is assessed using blood and urine testing.
  • Tests of blood and urine to determine the amounts of hormones that control blood pressure.

The following imaging test is used to diagnose renal artery stenosis:

  1. Doppler ultrasound

A Doppler ultrasound is a noninvasive diagnostic that uses high-frequency sound waves (ultrasound) to measure blood flow via your blood arteries by bouncing them off circulating red blood cells. 

A standard ultrasound utilizes sound waves to create visuals, but it can’t detect blood flow. A Doppler ultrasound can assess how rapidly blood flows by monitoring the rate of change in pitch (frequency).

Throughout a Doppler ultrasound, a sonographer presses a tiny handheld device (transducer) along your skin throughout the portion of your body being evaluated, going from one area to the other as needed. 

Your doctor may also use a Doppler ultrasound test to look for artery damage or track the progress of certain vein and artery treatments.

A Doppler ultrasonography can be used to identify a variety of issues, including:

  • Clots in the blood
  • Valves in your leg veins that aren’t working properly, causing blood or other fluids to collect in your legs (venous insufficiency)
  • Heart valve abnormalities and hereditary cardiac illness
  • An artery that is clogged (arterial occlusion)
  • Your legs’ blood flow is reduced (peripheral artery disease)
  • Arteries that are swollen (aneurysms)
  • Constriction of the aorta, especially in the neck (carotid artery stenosis)

Doppler ultrasound testing comes in a variety of forms. They are as follows:

  1. Color Doppler – Color Doppler – In this type of Doppler, sound waves are converted into unique colors using a pc. These colors represent the rate and path of blood circulation instantaneously.
  2. Power Doppler A power Doppler can provide you with additional details regarding blood circulation than a standard colour Doppler. It is unable to show the route of blood flow that is crucial in various situations.
  3. Doppler spectral – Instead of using colour visuals, this procedure includes a graph to depict blood flow statistics. It can help determine the amount of a blood vessels are constricted.
  4. Doppler Duplex – This evaluation uses Doppler Duplex ultrasound scanning of blood vessels and organs. The images are then converted into a graph, similar to spectral Doppler, by a computer.
  5. Continuous-wave Doppler – Sound waves are continuously sent and received in this test. It enables more precise blood flow measurement at higher speeds.

Procedure for Doppler ultrasound 

  1. Doppler ultrasound is a straightforward, painless, and risk-free treatment. It may be possible to get it conducted at a local clinic, or it could be necessary to visit the radiology sector of a hospital..
  2. The ultrasound technologist may use blood pressure sensors on the calves, ankles, or thighs to detect the pressure in various parts of the arms or legs.
  3. They then lubricate a transducer, which is a portable device that they use to produce a picture of the blood flow underneath the skin.
  4. The entire treatment takes about 30–45 minutes, and patients can usually leave right away.