Renal hypertension (renovascular hypertension, renal hypertension) is a condition in which the blood vessels that supply blood to the kidneys narrow. This gradually causes increased blood pressure (hypertension). Symptoms rarely occur in the early stages of this insidious and serious disease, but with very high blood pressure, the patient will experience blood in the urine, confusion and vision problems, among other symptoms. Most patients benefit from medication to treat high blood pressure, but sometimes medical treatments are needed to get blood pressure back under control.

• Causes of renal hypertension
• Risk factors of renal hypertension

• Atherosclerosis
• Fibromuscular dysplasia

• Symptoms

• Almost never draw
• Gradual organ damage

• Diagnosis and examinations
• Treatment of narrowed renal artery(s)
• Prognosis of problem with arteries of kidneys
• Prevention of high blood pressure by narrowing blood vessels

Causes of renal hypertension

The kidneys need blood to function properly. Renal hypertension is a narrowing of the blood vessels (vasoconstriction) that supply blood to the kidneys. The narrowing of the arteries occurs in one or both kidneys. This situation is known in medical terms as renal (artery) stenosis. Because the kidneys do not receive enough blood, the kidneys basically react incorrectly and think that the blood pressure is too low. They release the hormone renin, which causes the body to retain sodium and water. This causes extra fluid to enter the blood vessels, resulting in increased blood pressure.

Risk factors of renal hypertension

Smoking is a risk factor / Source: Geralt, Pixabay

Atherosclerosis

The most common cause of renal artery narrowing is due to high cholesterol. This problem occurs when a plaque (sticky, fatty substance) builds up on the inner lining of the arteries, causing a condition called atherosclerosis.Other risk factors for atherosclerosis include:

• cocaine abuse (drug abuse)
• diabetes mellitus
• high blood pressure (hypertension)
• high cholesterol
• an increasing age
• smoking
• heavy alcohol use

Fibromuscular dysplasia

Occasionally, the condition fibromuscular dysplasia is the cause of the narrowed renal arteries. This condition of unknown cause often occurs in women under the age of fifty. The condition results from an abnormal growth of cells in the walls of the arteries leading to the kidneys. Fibromuscular dysplasia also leads to a narrowing or blockage of these arteries.

Symptoms

Double vision is one of the possible signs, although like other symptoms it only appears at a late stage / Source: Nufkin, Flickr (CC BY-2.0)

Almost never draw

Renal hypertension is not accompanied by symptoms in most cases. The narrowing in the arteries is not palpable or visible. After all, high blood pressure only causes noticeable symptoms when it is dangerously high. The following possible signs occur with dangerously high renal hypertension:

• bloody (pink) urine (hematuria)
• a nosebleed (epistaxis)
• headache
• confusion
• blurred vision or double vision (diplopia)

Gradual organ damage

However, patients almost never experience one or more of these complaints. However, high blood pressure is dangerous, despite the fact that the patient does not experience any signs. Organ damage occurs gradually without the patient noticing. Renal hypertension sometimes causes chronic kidney disease, which gradually decreases kidney function. A patient with kidney failure also only experiences complaints at a late stage. Heart problems and lung diseases are also sometimes caused by renal hypertension.

Diagnosis and examinations

Most patients have no symptoms. However, if the patient has uncontrolled high blood pressure despite taking medication to treat the hypertension, this may indicate renal hypertension. A patient with an unexplained chronic kidney disease who has high blood pressure is also likely to suffer from renal hypertension. In addition to blood pressure measurement, the doctor carries out various tests such as a blood test, urine test, an ultrasound, CT scan and/or MRI scan of the kidneys, an angiography (radiographic examination of the blood vessels) and/or a biopsy of the kidneys.

Treatment of narrowed renal artery(s)

Various medications can be used / Source: Stevepb, PixabayMedication The doctor first uses medication to control high blood pressure in renal hypertension. The doctor often has to use a combination of medications to control blood pressure when renal hypertension is caused by a narrowing of the renal artery. The following medications can be used:

• ACE inhibitors (angiotensin-converting enzyme inhibitors). Examples include ramipril, benazepril, captopril, lisinopril and others.
• ARBs (angiotensin II receptor antagonists). Examples include candesartan, losartan, olmesartan and valsartan.

Other treatments In some patients, drug treatment is insufficiently effective to control blood pressure. The doctor then opts for one or more medical treatments.Angioplasty In angioplasty, a doctor places a catheter in the renal artery via a large artery in the groin. He then inflates a balloon with the aim of widening the artery so that blood flow improves.Surgery Sometimes a surgical procedure is necessary in which the surgeon bypasses the narrowed renal artery.Stenting The doctor sometimes places a stent in the renal artery to widen it.

Prognosis of problem with arteries of kidneys

If the medication does not produce sufficient results, surgical intervention is usually effective for the treatment of renal hypertension. A stenting procedure also produces effective results, but sometimes the doctor has to repeat the treatment. Angioplasty is generally less effective than the other treatment options. In general, procedures are more effective when one renal artery is narrowed than when both renal arteries are narrowed.Sufficient exercise is necessary / Source: Skeeze, Pixabay

Prevention of high blood pressure by narrowing blood vessels

Good preventative approaches for preventing renal hypertension include:

• control blood sugar levels (in diabetics)
• drink less alcohol
• drink less caffeine
• consume less salt
• perform physical activities for at least thirty minutes per day
• quit smoking
• avoid stress

read more

• Kidney Health: Tips for Healthy Kidneys & Good Kidney Function
• Kidney biopsy: Removal of a kidney tissue sample (kidney biopsy)
• Renal infarction: Decreased blood flow to kidneys
• Renal failure: Decreased or absent renal function
• Renal artery stenosis: Narrowing of arteries in kidneys