In the phrase “renal hypertension,” “renal” relates to your kidneys and “hypertension” means high blood pressure. This condition happens when the arteries that transport blood to your kidneys get smaller. Complications of renal hypertension include heart attack, aneurysm and stroke.
Renal hypertension (or renovascular hypertension) is high blood pressure caused by the narrowing of your arteries that carry blood to your kidneys. It is also sometimes called renal artery stenosis. Because your kidneys are not getting enough blood, they react by making a hormone that makes your blood pressure rise.
This condition is a treatable form of high blood pressure when properly diagnosed.
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Blood pressure is the force of blood against your artery walls as your heart pumps blood through your body. A reading of 120/80 mmHg, or “120 over 80,” is normal. A reading of 140/90 mmHg or above is considered high blood pressure. Blood pressure should be checked regularly.
High blood pressure puts increased stress on your blood vessels in the kidneys, including the filtering units that are responsible for cleaning your blood. Over time, these blood vessels can thicken, similar to other parts of the body, and the filtering units can form scars. Both of these changes can lead to your kidneys not working properly (chronic kidney disease) and they stop doing their job — removing wastes and extra fluid from your body. When your kidneys don’t work well they can cause further increases in blood pressure by releasing certain hormones or by causing retention of salt and water in your body.
High blood pressure is one of the leading causes of kidney failure.
Over 72 million Americans have hypertension. Less than two percent of cases are renal hypertension.
Men and women age 67 and older are more likely to have renal hypertension, but you can get it at any age. You’re more likely to have renal hypertension if you’re Caucasian instead of African American.
Renal hypertension is caused by a part or total bock of the arteries that supply blood to your kidneys. These renal (kidney) arteries carry blood rich in oxygen and nutrients from your heart to your kidneys. If your kidneys do not get enough blood or oxygen, it may be because these renal arteries are narrowed, a condition called renal artery stenosis.
Atherosclerosis, or hardening of the arteries, is the most common cause of renal artery stenosis. Plaque, made up of fat, cholesterol, calcium and other substances, builds up inside your arteries and causes them to harden and narrow (stenosis). Plaque can block, either partially or totally, your blood's flow through an artery in the heart, brain, pelvis, legs, arms or kidneys.
Another cause of renal artery stenosis is fibromuscular dysplasia (FMD). While the cause of FMD is not clear, it is different in that it is not caused by plaque build-up, but rather narrowing of your blood vessel walls themselves. FMD is more common in women and should be considered in younger people who develop high blood pressure.
Additional causes include:
Although renal hypertension is hard to diagnose and usually has no symptoms, be aware of these signs:
At this time there are no known foods or drinks that worsen or improve renal hypertension.
It is important to see your healthcare provider regularly to make sure your blood pressure numbers are checked and are within the normal range. He or she may recommend blood tests.
A healthcare provider can gather clues that vascular disease may be present by taking a thorough history and performing a physical exam. If you have a history of other vascular diseases, such as heart attacks or strokes, you are at higher risk for having renal artery stenosis. One exam, listening to the neck or belly with a stethoscope, may help identify narrowed arteries. When blood flows through a narrowed artery, it sometimes makes a whooshing sound, called a bruit.
Healthcare providers may order one of the imaging tests below to look for narrowed kidney arteries. However, finding a narrowed kidney artery alone does not mean that your high blood pressure is due to renal hypertension. Many people have narrowing of kidney arteries without high blood pressure or with high blood pressure that is not caused by the narrowing (essential hypertension). The healthcare provider will need to use other clinical clues to help determine if the two are connected.
Imaging tests that can be done to see if the kidneys’ arteries have narrowed include:
If your healthcare provider suspects you might have renal hypertension, you most likely are already on medicines to help control your blood pressure. There are many different types of high blood pressure medications available. Everyone responds to medicine differently. Your healthcare provider will decide which type is best. Remember:
The goal is to lower your blood pressure. In renal hypertension, two specific types of medications may work better to control your blood pressure:
These medications are rarely prescribed at the same time. In certain cases of renal artery stenosis where both arteries are narrowed, these medications may cause a decrease in kidney function. It is important that your healthcare provider check a blood test for your kidney function one to two weeks after starting or adjusting these medications. In addition to an ACE inhibitor or an ARB, a diuretic, or water pill, may be prescribed to help your kidneys remove extra fluid from the blood. The water pills will make you urinate more often.
Angioplasty with stenting is an invasive procedure that helps blood flow more freely through the artery to the kidney. It is an option for those who have:
In an angioplasty, a healthcare provider (perhaps a cardiologist, radiologist, or vascular surgeon, depending on who performs these procedures in your area) inserts a catheter into a small puncture over an artery in the arm or groin. This catheter carries a tiny inflatable balloon with it to the blocked area. There, the balloon is inflated and deflated (angioplasty) several times to flatten the plaque against the artery walls, widening the vessel. After the procedure, the balloon and catheter are removed from the body. Stenting is usually needed in addition to angioplasty.
With stenting, a tiny mesh tube, called a stent, is inserted by the catheter. Just like the balloon in an angioplasty, the stent is guided to the narrowed area of the renal artery and placed to provide support, keeping the artery open. The stent is left in place permanently.
If the condition does not improve with medication and/or angioplasty, or the narrowing recurs or cannot be stented for any reason, renal bypass surgery may be an option. By taking a vein or synthetic tube to connect your kidney to your aorta, the surgeon creates an alternate route, or bypass, for blood to flow around the blocked artery into your kidney. This procedure is complex and high risk and rarely used.
Angioplasty and stenting have not been shown to be better than controlling blood pressure with medications. This is because, in most people, renal artery stenosis may be present but does not cause high blood pressure. In such cases, opening up the artery will not result in improved blood pressure.
It is suggested that this procedure be reserved for those whose blood pressure cannot be controlled by medications, who experience unacceptable side effects with their blood pressure medications, who developed rapidly worsening kidney function or who have a rapid build-up of fluid in their lungs called flash pulmonary edema.
There are no at-home remedies that can help with renal hypertension. However, you should always take your medicines as prescribed, eat healthy and follow your healthcare provider’s instructions.
In theory, if the renal artery stenosis is reversed, then the hypertension should improve.
If you have renal hypertension, you might experience the following complications that are caused by high blood pressure, including:
A healthy lifestyle is key to helping control any type of hypertension. Making changes in daily habits can help, such as:
If you don’t get your renal hypertension treated, you might end up having end-stage renal failure (your kidney will not work anymore). The median survival time of someone with end-stage renal failure is about two years.
Take your medicines and do your best to keep your blood pressure low. Keep your body healthy by eating right, exercising and quitting smoking. Follow up with your appointments with your healthcare provider.
What questions should I ask my healthcare provider about renal hypertension?
A note from Cleveland Clinic
Renal hypertension is a very serious disease. You and your healthcare provider need to pay close attention to your blood pressure. High blood pressure (hypertension) can cause heart attack, aneurysm and stroke, among other complications. Work with your healthcare provider to figure out the best treatment and be sure to take all medications and follow all post-operative instructions perfectly.
Last reviewed by a Cleveland Clinic medical professional on 12/14/2020.
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