Understanding Renal Arterial Disease: Symptoms, Causes, Treatment & Prevention

Renal arterial disease, which is also referred to as renal artery stenosis (RAS), is characterized by the narrowing of one or both of the arteries that supply blood to the kidneys. This is most often the result of excessive plaque buildup in the renal arteries, but it can also occur as a side effect of other conditions and even medical treatments—ranging from congenital conditions present at birth to post-surgical complications. It is a known cause of hypertension and, like that condition, renal arterial disease often goes undetected until after it has progressed.

Renal arterial disease is a condition that is most prevalent among people over the age of 60, and if not treated properly, it can lead to possible kidney damage and/or high blood pressure. Because it shares many of the same symptoms as both hypertension and reduced kidney function, it shouldn’t be overlooked by patients seeking treatment for either condition.

Fortunately for many patients, timely diagnosis can prevent the disease from causing any of its most serious complications, and the methods of management for this condition are also good for one’s overall cardiovascular health.

What are the Causes & Risk Factors of Renal Arterial Disease?

Renal arterial disease has several known causes:

Atherosclerosis

It is most often caused by atherosclerosis, which is the buildup of plaque inside the arteries. Plaque is commonly comprised of fat, cholesterol, calcium and other substances, and over time it can limit the flow of blood to your organs and other parts of your body. Eventually, these plaque deposits can harden and cause kidney scarring as they grow in size and narrow the affected renal arteries. Potential causes of atherosclerosis can include diabetes, high cholesterol, chronic kidney disease, tobacco use and hypertension. According to the National Institutes of Health, anywhere from 60% to 90% of cases of renal arterial disease are caused by atherosclerosis.

Fibromuscular Disease

Another prominent cause of renal arterial disease is fibromuscular disease (or dysplasia), a condition that is sometimes present at birth (congenital), sometimes linked to injuries or outside factors and more often found in women than in men. This condition either prevents the muscles in the artery wall from developing properly or causes them to become misshapen, which can lead to certain sections becoming narrow enough to reduce blood flow. Unlike atherosclerosis, there is no known cause of fibromuscular dysplasia. The NIH estimates that this is the cause of renal arterial disease in approximately 10% to 30% of cases.

Additional Causes

It is possible, though rare, for renal arterial disease to develop as a result of pressure on the renal arteries due to an abdominal growth, inflamed blood vessels (vasculitis), blood clots (thromboembolism) and various other conditions. According to the NIH, these conditions cause renal arterial disease in less than 10% of patients.

Risk Factors for Renal Arterial Disease

While atherosclerosis is by far the most prominent risk factor for renal arterial disease, there are many other conditions, lifestyle choices and genetic factors that have been linked to RAS. These risk factors include:

• Diabetes
• Family history of early cardiovascular disease
• Fibromuscular disease
• High blood pressure
• High cholesterol
• Lack of exercise
• Obesity
• Poor diet (high in cholesterol, fat, sodium and sugar)
• Smoking

Additionally, people over the age of 45 are at greater risk of developing renal arterial disease. It is most often diagnosed in men older than 45 and in women older than 55.

Risk Reduction

It is possible to reduce the risk of developing renal arterial disease through healthy lifestyle choices primarily aimed at reducing high blood pressure and improving one’s overall cardiovascular health:

• Eating a well-balanced diet that is low in sodium
• Exercising regularly
• Losing weight and maintaining a healthy weight once it’s reached
• Lowering stress levels
• Maintaining a healthy blood pressure number
• Reducing alcohol intake or quitting altogether
• Quitting smoking

If you have a family history of heart disease, particularly if relatives have developed it at an early age, taking the preventive measures above can effectively reduce your risk of developing renal arterial disease.

What are the Symptoms & Warning Signs of Renal Arterial Disease?

Renal arterial disease involves the narrowing of artery walls, so it can essentially be considered a “silent” disease. There simply isn’t a way for people to know that they have this specific condition without being examined by a medical professional. And because the condition itself doesn’t typically cause symptoms, it’s not always detected until after the disease has already progressed to an advanced stage. The first sign of RAS is usually high blood pressure, and reduced kidney function will eventually follow. Other signs and symptoms may include:

• An unexplained increase in blood pressure
• Development of hypertension before age 30 or after age 50
• Difficulty controlling blood pressure
• Heart disease that resists the effects of medications
• Reduced kidney function during treatment for hypertension

When to Seek Urgent Medical Care

If you are experiencing any of the above symptoms, you should talk to your medical care provider about testing for renal arterial disease. However, you should seek medical care right away if you are experiencing any of the following symptoms of high blood pressure and/or poor kidney function:

• Abdominal pain
• Changes to the skin
• Headaches
• Inability to concentrate
• Inability to sleep well
• Loss of appetite
• Metallic taste in the mouth
• More frequent or infrequent urination
• Muscle cramping
• Nausea and vomiting
• Physically and/or mentally fatigued
• Shortness of breath
• Swelling in the legs, arms or face
• Unexplained weight loss

Experiencing these symptoms does not always mean that a patient has renal arterial disease in addition to hypertension or reduced kidney function, but RAS has been clearly linked to these conditions as an underlying cause worth checking for.

Diagnosis & Tests for Renal Arterial Disease

Because renal arterial disease often leads to hypertension and/or reduced kidney function, it’s often caught while a healthcare provider is diagnosing or treating another condition. A thorough review of the patient’s medical history, their current symptoms and their family’s medical history will be used to determine the risk level a patient has for developing—or unknowingly living with—renal arterial disease.

Tests that are used to detect RAS include:

• Blood and urine testing – These tests are used to evaluate one’s kidney function and can detect unusual levels of waste products (such as protein and nitrogen) in your bodily fluids—a sign that your kidneys aren’t working properly.
• Blood pressure testing – Because high blood pressure is a symptom of renal arterial disease, it’s important to start with this test.
• Checks for swelling of the limbs – Fluid buildup (edema) in your feet, ankles or arms can indicate reduced blood flow.
• Coronary angiogram – This is a test designed to evaluate how well blood flows through the heart using contrast medium dye and x-rays. These are typically ordered in an effort to check for a broad spectrum of possible heart conditions rather than to simply look for renal arterial disease.
• Stethoscope – Sometimes, when blood travels through a narrowed artery, it can make a specific “whoosh” sound called a bruit that a doctor can hear when placing a stethoscope on the front or side of the patient’s abdomen.
• Various imaging scans – Ultrasounds, CT scans, magnetic resonance angiography (MRA) and renal arteriography are used to evaluate your kidney function based on the size of your kidneys and the nature of the blood flow from the heart to the kidneys.

How Do You Treat Renal Arterial Disease?

For milder cases of renal arterial disease, a medical care provider will only recommend medications and certain lifestyle changes to manage and treat the condition.

Medications & Lifestyle Changes

There are several drugs that can help patients manage and treat the condition, including:

• Aspirin – As a blood thinner, aspirin can make it easier for blood to flow through the arteries and more effectively reach the kidneys.
• Beta-blockers and calcium channel blockers – Drugs that are often used to reduce high blood pressure by relaxing the blood vessels can also be effective at treating renal arterial disease.
• Diuretics – Also called “water pills,” diuretics allow your kidneys to remove excess sodium and water from the blood.
• Hormone blockers – Because some hormones can cause the blood vessels to narrow, ACE (angiotensin-converting enzyme) inhibitors and ARBs (angiotensin receptor blockers) may be used to prevent this occurrence.
• Statins – This medication is used to treat high cholesterol, which is one of the causes of atherosclerosis.

These medications can be effective, especially when combined with any lifestyle changes a doctor may recommend. That could include exercise, diet changes, stress reduction, smoking cessation and other practices that are also used to reduce the risk of developing high blood pressure and related conditions such as renal arterial disease.

Surgery to Treat Renal Arterial Disease

Surgery is not likely to be recommended when a patient has a mild or moderate case of renal arterial disease. It is usually reserved for greater degrees of arterial blockage and more advanced stages of RAS, which includes:

• A high risk of arterial occlusion (blockage)
• Progressive loss of kidney function
• Severe renal artery stenosis

If you have been diagnosed with a more severe case of renal arterial disease, there are several potential surgical treatment options that your medical care provider can recommend, including:

• Renal angioplasty and stenting – In this procedure, a surgeon inserts a catheter into the affected area and inflates a balloon that flattens the plaque onto the artery’s walls. A small wire tube (stent) is then inserted to help keep the artery open.
• Renal artery bypass – In this treatment option, which is usually used for more severe cases, a substitute artery is grafted to the renal artery to create a new path for blood to reach the kidneys.
• Renal endarterectomy – This procedure entails the removal of the plaque from the renal artery through an incision in the aorta, which is then stitched closed.

If renal arterial disease is caught early enough, it can be successfully treated and managed with the above treatment methods as well as follow-up care and monitoring by a doctor.

What are the Complications & Long-Term Effects of Renal Arterial Disease?

Because renal arterial disease makes it difficult for blood to travel from the heart to the kidneys, it can cause chronic kidney disease or outright kidney failure if left untreated. In addition to kidney damage, if left untreated this condition can cause the body to sense the reduced blood flow to the kidneys and mistake this for low blood pressure, which it then attempts to correct by raising the blood pressure. This leads to hypertension.

Atherosclerosis can also cause a condition called peripheral artery disease (PAD), in which blood flow from the heart to the arms and legs is reduced as a result of those arteries narrowing. It is possible for patients with renal arterial disease to also develop PAD, or vice versa.

Prognosis

While renal arterial disease is treatable and many patients are able to manage or overcome their condition, a patient’s prognosis depends on the progression of their condition. Roughly half of all people with near-total renal artery blockage (greater than 95%) live for four more years after they are diagnosed.

Living with Renal Arterial Disease

Not only it is possible to live an active, healthy lifestyle with renal arterial disease, it’s a doctor-recommended course of action for treating and managing the condition. Patients are often asked to:

• Adjust their diet – Cutting down on one’s sodium intake, as well as reducing the amounts of sugars, fats and cholesterol in the diet, has been proven to reduce blood pressure. Salt, in particular, is known to increase blood pressure by increasing the volume of the blood while the body retains more fluid.
• Exercise regularly – Staying active can strengthen the heart, reduce blood pressure and improve one’s overall quality of life—in addition to treating renal arterial disease.
• Keep a healthy body weight – Losing weight can be difficult, and keeping that weight off can be even more challenging, but doing so can make a world of difference in patients who are treating their renal arterial disease. This is because blood pressure increases along with one’s weight.
• Manage their stress levels – Taking steps to reduce the amount of stress in one’s day-to-day life, or even changing their lifestyle to cut out certain stressful activities, can keep blood pressure more consistent.
• Quit smoking and reduce drinking – Smoking has been proven to make arterial stenosis worse, and drinking too much alcohol can increase blood pressure.

Some of these lifestyle changes may be difficult for patients to make on their own. It’s recommended to talk to a medical care provider to:

• Begin a new exercise program, especially if you haven’t been physically active for a long time
• Develop a healthy diet that works for you
• Get help with quitting smoking
• Identify an ideal body weight goal to work toward

Your doctor may also be able to provide you with educational resources to help you more easily adjust to a completely new lifestyle.

Renal Arterial Disease: Frequently Asked Questions (FAQs)

Whether you’ve recently been diagnosed with renal arterial disease or are simply trying to learn more about this condition, you likely have many questions about it. Frequently asked questions include:

• What causes renal arterial disease? – Usually, RAS is caused by an excessive buildup of plaque in the renal arteries (atherosclerosis) that deliver blood to the kidneys. Sometimes, it’s caused by fibromuscular disease, a condition for which a cause is not known. It is uncommon, but not unheard of, for RAS have other causes.
• What are signs of renal arterial disease? – The two most common signs of RAS are high blood pressure and reduced kidney function.
• What are symptoms of renal arterial disease? – RAS typically has no symptoms until it has progressed enough to become severe. At that point, it will share the symptoms of high blood pressure and poor kidney function.
• How is renal arterial disease diagnosed? – Your medical care provider can diagnose the condition with a physical exam, imaging scans, blood and urine testing and in some cases, during a coronary angiogram meant to catch other kinds of heart problems.
• Can renal arterial disease be treated? – Yes, it is possible to manage and treat this condition with some combination of medication and lifestyle changes, as well as surgery in severe cases.
• What happens if renal arterial disease isn’t treated? – Patients with untreated RAS are at risk of developing hypertension, chronic kidney disease, kidney failure and other conditions such as coronary artery disease and stroke.

The TGH Difference for Renal Arterial Disease

Renal arterial disease is a condition that often goes undetected until it has already advanced but can be treated with a variety of methods. Many patients who develop this condition can go on to lead normal, healthy lives when proper treatment guidelines are followed.

At Tampa General Hospital, our team of cardiovascular specialists provides comprehensive care for a wide variety of conditions such as renal arterial disease. Our Heart & Vascular Institute has been recognized by U.S. News & World Report as One of the Nation’s Best Hospitals for Heart & Vascular Care, and “High Performing" for Heart Attack and Heart Failure, meaning we are ranked in the top 10% of all hospitals in the nation for 2024-25. We offer patients world-class care, no matter the severity of their condition and overall health.

Call us today at (813) 844-3900 to schedule an appointment with our Heart & Vascular team or email heart-vascular@tgh.org.