Renal Hypertension: Learn More About The Causes, Symptoms, And Treatment Options

Primary care physicians routinely monitor your blood pressure, as it can be a good indicator of heart health and may help them diagnose other underlying medical conditions. 

Blood pressure is the measurement of the force blood places on the walls of your arteries as it moves through your body. It can reflect how much blood volume you have, how fast your heart is beating, and if there’s any narrowing in the blood vessels.

Blood pressure is within the normal range if it's under 120 over 80 (or 120/80). Blood pressure above that may be considered elevated. If it's especially high, your doctor may diagnose you with hypertension or high blood pressure.

Hypertension is a very common medical condition, affecting more than 70 million American adults.¹ Renal hypertension, also called renal vascular hypertension, is a medical condition that affects the kidneys. It is one of the less common causes of hypertension, affecting only around 2% of those with hypertension.

The condition most often occurs when the arteries leading to the kidneys narrow or harden, sometimes called renal artery stenosis. The kidneys require blood to gain oxygen and other nutrients to work correctly. When they aren't getting sufficient blood supply, they stop sending a hormone out to the body that regulates blood pressure.

High blood pressure can also cause damage to other organs in the body, especially the heart, as the elevated blood pressure means the heart will need to pump harder to supply blood throughout the body. That can lead to serious medical issues.

If you've been diagnosed with renal hypertension, it's important to know what it means, how it may affect you, and the available treatment options.

Renal hypertension symptoms

Most people won't notice if they have hypertension. It's often called the Silent Killer because people don't know they have it until their blood pressure becomes so dangerously high that it causes a medical emergency, such as a heart attack or stroke. This can give hypertension time to do a lot of damage to the body before it's properly diagnosed and treated.

Renal hypertension is similar. Because you can't feel the arteries supplying blood to your kidneys, it is impossible to know if you are suffering from this medical condition. Without a diagnosis and treatment, renal vascular hypertension can lead to chronic kidney disease. When the kidneys aren't working properly due to renal hypertension, you may experience symptoms including:

• Chest pains

• Muscle cramps

• Shortness of breath

• Nausea

• Unexplained weight loss

• Numb, dry, or itchy skin

• Fatigue

• Memory loss

• Headaches

• Fluid retention causing swelling in the legs, arms, and fluid depositing in the  lungs

If you have a history of hypertension and start to experience any of these symptoms, contact your doctor right away. They may be signs of renal hypertension, but they may also be symptoms of other medical conditions like heart disease or advanced kidney failure.

Renal hypertension treatment

There are a variety of treatment options for renal hypertension. Early treatment can help prevent complications, such as kidney failure, heart attacks, and strokes. Your doctor will work with you to create the best treatment plan for your condition and lifestyle. 

Treatment plans may include a combination of medications, lifestyle changes, and surgical interventions. 

Medication

Medication is usually the first-line treatment for hypertension, including renal hypertension. There are various medication options, and everyone responds to medication differently. Your doctor may prescribe a combination of antihypertensive medications, depending on your symptoms. They may also prescribe diuretics, which help move fluid through your kidneys faster. 

Lifestyle changes

Making small changes to your lifestyle can help prevent the development of renal hypertension. These changes can also help you lower your blood pressure levels after a diagnosis of renal hypertension. Some common lifestyle changes that can make a difference include: 

• Losing weight or maintaining a healthy body weight 

• Increasing the amount of exercise you get each week

• Stopping smoking and reducing the amount of alcohol you drink

• Lowering stress and anxiety levels

• Eating more heart-healthy foods, such as whole grains and fatty fish

• Reducing salt intake to decrease fluid retention and blood pressure

Your doctor can help you identify potential lifestyle changes you can make to manage your high blood pressure. With the help of medication, many people can successfully manage their blood pressure without surgery. 

Surgery

If medication and lifestyle changes aren't helping to keep your blood pressure under control and restore the function of the kidneys, then surgery may be the next best option. It may also be used if you have severe complications, such as fluid in the lungs, strokes, etc. Surgical options for renal vascular hypertension include:

Angioplasty

During this surgical procedure, a doctor inflates a balloon in the constricted artery supplying blood to the kidneys. Inflating the balloon momentarily will help widen the artery. This helps blood flow to the kidneys more freely.

Stenting

Like angioplasty, a surgeon uses a balloon to inflate the renal artery. Before they remove the balloon, they put a stent in place. The stent is a small piece of wire mesh designed to stay in the artery, widening it and improving blood flow.

Redirect blood flow

If an angioplasty or stenting isn't possible, a surgeon may be able to redirect blood flow from the blocked or narrowed artery to the kidneys. They do this by taking a healthy artery and attaching it next to the damaged one. Blood flow will then redirect automatically to the kidneys.

These surgeries are generally considered low risk and may even be done as outpatient procedures. However, they may require repeat treatments or may not work if the problem with the kidney has been around for a long time. There is also a rare chance of damaging the artery to the kidney. Any surgery would only be recommended if there was a high likelihood of improvement and would need to be discussed with your treating doctor.

How is renal hypertension diagnosed?

Most people won't experience any symptoms of renal hypertension until there is significant damage to the kidneys. Many people are first diagnosed with renal hypertension after visiting their doctor and a routine blood pressure check. If your blood pressure is high, your doctor may run some tests to determine if an underlying medical condition may be causing it. They will also want to learn more about your medical history as well as your family's history of renal or cardiac conditions.

If your doctor believes your high blood pressure is a result of a blockage in the renal arteries, they may request imaging tests, such as:

Duplex ultrasound

This will show the blood flow through the kidney arteries and may reveal typical findings in keeping with narrowed vessels (“beading,” “string” like appearance, etc.).

Catheter angiogram

A doctor will insert a small tube into your renal artery and inject a small amount of dye. They will then take an x-ray. The dye will help them see the renal artery more clearly and identify if there are any issues. Often, any issues can then be treated at the same time.

Computerized tomographic angioplasty (CTA)

This imaging also uses contrast dye and x-rays, but computers help enhance the x-ray image. There is a small amount of radiation, but some patients prefer this option because it is less claustrophobic than an MRI.

Magnetic resonance angiogram (MRA)

This process also uses a contrast dye to enhance the image of the renal artery on screen. Instead of an x-ray, though, the image will come from an MRI machine. There is no radiation used, but some patients may find the MRI to be claustrophobic.

Blood and urine tests can also help confirm any damage to the kidneys. Once diagnosed, your doctor can work with you to develop a treatment plan to manage high blood pressure levels and reduce the risk of further damage to the kidneys.

How is kidney function related to blood pressure?

High blood pressure can cause damage to the kidney. It may also be caused by the kidneys.

Over time, high blood pressure can start to damage your blood vessels. The pressure can cause them to lose their elasticity and make them narrow and harden. This makes it more difficult for blood to flow through the body and reach your organs, supplying them with oxygen and nutrients. Over time, this can harm organs such as the kidneys.

Your kidneys do a lot for your circulatory system, including cleaning and filtering blood. The kidneys are responsible for removing waste and extra fluids from the blood, then helping pass the waste out of the body as urine.

High blood pressure may damage the kidneys and make them less efficient at filtering. The extra waste in your system could cause your blood pressure to rise even more.

Kidneys also produce a hormone called aldosterone.² This hormone helps regulate your blood pressure and keep it in a normal range. If the kidneys aren't healthy enough to produce the hormone, your body won't be able to regulate your blood pressure efficiently.

This means that high blood pressure can damage the kidneys, and damaged kidneys can cause high blood pressure. This can become a dangerous cycle. If untreated, it could eventually lead to kidney failure. High blood pressure is the second leading cause of kidney failure.³

Renal hypertension causes

Some medical conditions may lead to renal vascular hypertension, and some genetic factors may increase your risk of developing the condition.

Any medical condition that impacts the blood supply to your kidneys could cause renal hypertension. The most common causes of the condition include:

Atherosclerotic renal artery stenosis

This is the most common cause of renal hypertension, responsible for every nine out of 10 cases. This happens when the arteries supplying the kidneys narrow, usually because of plaque build-up. This is more likely to occur in smokers, patients with high cholesterol, obesity, or histories of heart disease and strokes. It tends to occur in older patients.

Fibromuscular dysplasia

This is the second most common cause of renal vascular hypertension and is more common in younger females. This disorder causes cells in the arteries to become fibrous instead of elastic.

Renal hypertension may also be caused by inflammation in the arteries, as a side effect of radiation therapy, or as a result of surgery or injury that damages the arteries supplying the kidneys. It may also be caused by high blood pressure due to certain prescription medications and lifestyle choices.

Research suggests that there are genetic factors that may increase your risk of renal hypertension.⁴ If you have a relative with this medical condition, you are more likely to develop it yourself. 

The lowdown

Renal hypertension is high blood pressure caused by damage to the kidneys or the renal system. While high blood pressure is a common medical condition, only about 2% of those with hypertension have renal hypertension. The condition occurs when the arteries that supply the kidneys with blood become narrow, hardened, or damaged. This causes the kidneys to stop filtering blood properly and prevents them from sending out a blood-pressure regulating hormone. That means high blood pressure can cause kidney damage, and kidney damage can cause high blood pressure. This can create a dangerous cycle that could lead to chronic kidney disease or kidney failure.

There can be no symptoms of hypertension, and most people won't be aware that they have the condition until they visit a doctor. Diagnosis usually begins with a blood pressure check that indicates a problem. Imaging with x-rays, MRIs, and ultrasounds can help doctors make a renal hypertension diagnosis along with blood and urine tests.

If diagnosed and treated early, this is a potentially treatable form of hypertension. Most people respond well to a combination of medications and lifestyle changes. However, in cases where patients are not responding to these treatments, surgery may be required. Angioplasties and stents can widen the renal arteries and increase blood flow to the kidneys.

If you have a history of kidney or heart problems or a family history of high blood pressure, talk to your doctor about how to monitor your blood pressure. They can also help you identify changes you can make to your lifestyle to reduce your risk of developing renal hypertension.