What is renovascular hypertension?Renovascular hypertension is a secondary form of high blood pressure caused by a narrowing of the renal artery. Narrowing of the renal artery reduces the flow of blood to the kidney. The kidney, sensing an artificially reduced blood flow, sends out signals to the rest of the body to raise the blood pressure. As with primary hypertension, symptoms are often absent or
subtle. Renovascular hypertension is the most common form of secondary hypertension and affects no more than five percent of all adults with hypertension. There are two forms of renovascular hypertension.
Hypertension is another name for high blood pressure. Renovascular hypertension is a form of what is called secondary hypertension, which is hypertension caused by another condition in the body. In this case, the high blood pressure is caused by the hardening and narrowing of the renal artery, which carries blood to the kidneys. Narrowing of the renal artery is called renal artery stenosis. Renovascular hypertension occurs more often in white men and blacks of both sexes. It occurs in approximately 6 out of 100,000 people. Age of onset depends upon the cause of damage to the kidney blood vessels. It often occurs in men over the age of 45 with atherosclerosis, and in women under the age of 45 with fibromuscular dysplasia. Around 10% of children with fibromuscular dysplasia also develop renovascular hypertension. Smoking, eating a diet high in salt, obesity, high levels of stress, frequent exposure to heavy metals, and a family history of hypertension increase a person's risks of developing this condition.
The main symptom of renovascular hypertension is high blood pressure. Blood pressure is recorded in two values. The top number, called the systolic, is taken when the heart contracts. It is considered normal when it is below 130. The bottom number, the diastolic blood pressure, reflects the pressure in blood vessels when the heart is at rest. It should be below 90, but in people with renovascular hypertension, the diastolic pressure is often higher than 104. Other symptoms depend upon the severity and cause of the disease, and can include headache, fatigue, nausea and vomiting, chest pain, vision problems, confusion, anxiety, excessive perspiration, and pale or reddened skin. However, many people will have no symptoms at all. When renovascular hypertension is caused by a blood clot in a renal artery, the patient will usually have a sudden pain in the side and bloody urine. Renovascular hypertension can lead to many serious complications, including hypertensive heart disease, stroke, blindness, myocardial infarction, congestive heart failure, blood vessel damage, kidney damage, and kidney failure.
The goal of treatment for renovascular hypertension is to control the high blood pressure. Your doctor may first recommend some lifestyle changes that may be aggravating your hypertension. For example, you may need to lose weight, get more exercise, or change your diet so it is lower in fat and salt. If you smoke or drink alcohol frequently you should stop because both can cause serious complications for someone with renovascular hypertension. Frequently used medications include diuretics, which help the kidneys eliminate salt and water; potassium supplements, because diuretics cause a loss of potassium; beta blockers, which stop the nervous system from raising blood pressure during stress; and calcium channel blockers and angiotensin-converting enzyme inhibitors, both of which lower blood pressure by dilating the arteries. Drugs such as diazoxide or nitroprusside are given in hypertensive emergencies where the blood pressure must be lowered quickly. Treatment is extremely individual and your doctor may need to try several different medications before finding the one that is right for you. Your doctor will want to monitor your blood pressure and medications frequently. Renovascular hypertension does not always respond well to anti-hypertensive drugs. In these cases, the narrowed artery to the kidney can be dilated with a balloon catheter. A balloon catheter is a long, thin tube with a small balloon at the end. After the catheter is inserted into the kidney, the balloon is inflated to open the narrowed artery. This procedure is often effective for patients with fibromuscular dysplasia. Surgery may also be performed to repair or bypass the narrowed part of the artery supplying the kidney. If the kidney has been severely damaged, it may need to be removed.
More information on high blood pressureWhat is blood pressure? - Blood pressure or arterial blood pressure is the pressure (force per unit area) exerted by the blood on the walls of the blood vessels.
What is high blood pressure (hypertension)? - High blood pressure or hypertension means high pressure (tension) in the arteries. High blood pressure is generally defined as a level exceeding 140/90 mm Hg that has been confirmed on multiple occasions.
How to measure blood pressure? - Arterial blood pressure is usually measured in millimeters of mercury (mm Hg) using a sphygmomanometer.
What causes high blood pressure? - High blood pressure is far more common in families where other members have this condition. There are also many other factors which are related to high blood pressure.
At what level is blood pressure too high? - Blood pressure is generally felt to be abnormally high at a level of 140/90, and some sort of definitive therapy and follow-up should be started at this level.
What is "white coat syndrome"? - "White coat syndrome" is a situation where patients have high blood pressure in the doctor's office but nowhere else.
What're the symptoms of high blood pressure? - High blood pressure usually causes no symptoms. Sometimes people with high blood pressure have symptoms including headache, dizziness, blurred vision and nausea.
How is high blood pressure diagnosed? - The diagnosis of high blood pressure is made on the basis of many blood pressure readings. It is diagnosed if several readings show a systolic blood pressure greater than 140 or a diastolic blood pressure greater than 90.
What is isolated systolic hypertension? - Isolated systolic hypertension (ISH) is defined as elevated systolic blood pressure in conjunction with normal diastolic blood pressure (<90 mm Hg).
Why and how isolated systolic hypertension (ISH ) develops? - Factors that may play a role in the high prevalence of ISH seen in Western societies include increased body fat, sedentary lifestyle, and increased sodium intake.
What is white coat hypertension? - White coat hypertension should be considered when blood pressure readings are significantly elevated in the absence of target-organ damage.
What is borderline hypertension? - Borderline hypertension is a blood pressure level which is in the 'gray zone' between normal and high (for example, someone with an average pressure of about 140/90 mmHg).
What is malignant hypertension (arteriolar nephrosclerosis)? - Malignant hypertension is an acute emergency requiring immediate treatment in hospital.
What is labile hypertension? - 'Labile' means variable, and just about everyone with hypertension has 'lablie hypertension.'
What is pulmonary hypertension? - Pulmonary hypertension is high blood pressure in the pulmonary circulation (the arteries which go to the lungs). The blood pressure in the arms and the rest of the body is normal or low.
What is renovascular hypertension? - Renovascular hypertension is a secondary form of high blood pressure caused by a narrowing of the renal artery.
What're the risk factors for high blood pressure? - Controllable factors contribute to high blood pressure include sodium (salt) sensitivity, obesity and overweight, heavy alcohol consumption, use of oral contraceptives and some other medications, and sedentary or inactive lifestyle.
What're the complications of high blood pressure? - Blood vessels can narrow due to high blood pressure and the accumulation of cholesterol. Blockage of arteries in the brain can lead to stroke. Blockage of blood vessels in the kidneys can lead to kidney failure.
How does body weight affect hypertension? - Studies have shown that body weight, changes in body weight over time, and skinfold thickness are related to changes in blood pressure levels.
What're the treatment options for high blood pressure? - The goal of treatment is to reduce blood pressure to a level where there is decreased risk of complications. Treatment may occur at home with close supervision by the health care provider, or may occur in the hospital.
What medications are available for high blood pressure? - Medications may include diuretics, beta-blockers, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), or alpha blockers.
Which lifestyle modifications are beneficial in treating hypertension? - Lifestyle modifications refer to certain specific recommendations for changes in diet and exercise.
What is a good high blood pressure diet? - A good high blood pressure diet is not only rich in important nutrients and fiber but also includes foods that contain far more electrolytes, potassium, calcium, and magnesium, than are found in the average American diet.