Your kidneys play an important role in keeping your blood pressure in a healthy range. In turn, your blood pressure can also affect the health of your kidneys.
"Hypertension, which is commonly referred to as high blood pressure, can damage the kidneys," explained Nephrologist Hilmer Negrete, M.D. "Blood pressure measures the force of blood against the walls of your blood vessels as your heart pumps blood throughout the body. If this pressure becomes too high, a person is said to have high blood pressure."
"When high blood pressure occurs, the heart must work harder. Over time, high blood pressure can damage blood vessels, which can reduce the blood supply to important organs like the kidneys. High blood pressure also damages the tiny filtering units in the kidneys. As a result, the kidneys may stop removing wastes and extra fluid from the blood, causing it to build up and raise blood pressure even more."
Links to Kidney Disease
High blood pressure is also a leading cause of chronic kidney disease. "Chronic kidney disease includes conditions that damage the kidneys and decrease their ability to function properly," Dr. Negrete continued.
As kidney disease progresses, the kidneys are less able to do the following jobs to help maintain good health:
- Remove wastes and extra fluid from the body
- Release hormones that help to:
- Control blood pressure
-- Promote strong bones
- Prevent anemia by increasing the number of red blood cells in the body
- Keep the right balance of important chemicals in the blood, such as sodium, potassium, phosphorus and calcium
-- Maintain the body's balance of acid and base.
"These problems may happen slowly over a long period of time, often without symptoms," Dr. Negrete said. "Chronic kidney disease may eventually lead to kidney failure requiring dialysis or a kidney transplant to maintain life. Every year, high blood pressure causes more than 15,000 new cases of kidney failure in the United States However, early detection and treatment can prevent or delay these complications."
Kidney damage, like hypertension, may be unnoticeable and is sometimes detected only through medical tests. "A physician may refer a person for blood tests, such as serum creatinine and BUN, which stands for blood urea nitrogen," Dr. Negrete stated.
"These tests will show whether the kidneys are removing wastes efficiently. Too much creatinine and urea nitrogen in the blood is a sign that a person may have kidney damage."
Another sign of kidney damage is proteinuria, or protein in the urine. "Proteinuria has also been shown to be associated with heart disease and damaged blood vessels," Dr. Negrete said. "In people with high blood pressure, proteinuria is an indicator of declining kidney function."
Controlling Blood Pressure
"If you have chronic kidney disease, high blood pressure makes it more likely that your kidney disease will get worse and you may develop heart problems," Dr. Negrete advised. "By following your treatment plan and keeping your blood pressure controlled, you can help keep your kidney disease from getting worse and prevent heart disease."
Normal blood pressure in adults 18 and older is less than 120/80 mm/hg. People who have blood pressure between 120 and 139 mm/hg for the top number, or between 80 and 89 mm/hg for the bottom number, may be more likely to develop high blood pressure unless they take steps to prevent it. In general, blood pressure that stays at 140/90 mm/hg or higher is considered high.
However, for people who have diabetes or chronic kidney disease, a blood pressure of 130/80 mm/hg or higher is considered high.
"Many people need medications to control their high blood pressure," Dr. Negrete concluded. "Two groups of medications called ACE inhibitors and angiotensin receptor blockers, lower blood pressure and have an added protective effect on the kidney in people with diabetes.
"Studies have shown that these medications also reduce proteinuria and may slow the progression of kidney damage in some people, who do not have diabetes. Individuals with hypertension or those at an increased risk for kidney disease, should consult with their physician for early management of their high blood pressure."
Hilmer Negrete, M.D., is a board certified nephrologist affiliated with Salem Community Hospital's medical staff. Appointments with Dr. Negrete can be scheduled at Salem Community Hospital's outpatient department by calling his office, 330-759-0059, at 807 Southwestern Run in Boardman.