High blood pressure makes your heart work harder and damages blood vessels throughout your body, including those in your kidneys. This can lead to kidney damage and failure. Each year, high blood pressure causes more than 25,000 new cases of kidney failure in the U.S., according to the National Institutes of Health (NIH).
Damaged kidneys cannot filter wastes and extra fluids from the blood, raising blood pressure even more and creating a dangerous cycle. Unfortunately, both high blood pressure and kidney damage often go unnoticed. To avoid this deadly combination, you first need to learn where you stand: Is your blood pressure normal? Are your kidneys working properly?
To find the answers, your doctor will first check your blood pressure, then take a simple blood test to measure the levels of creatinine and blood urea nitrogen, or BUN. High levels indicate your kidneys are not filtering wastes efficiently, a sign of organ damage. Your doctor will also test your urine to measure its protein levels. Too much protein, a condition called proteinuria, also signals impaired kidney function.
To prevent further damage, you must keep your blood pressure below 130/80 mm HG. (Normal pressure is less than 120/80 mm HG.) The NIH recommends people with signs of kidney damage use whatever therapy needed—lifestyle and diet changes and medication—to achieve this, including:
- maintaining optimal weight
- limiting your daily salt intake to less than 2,000 milligrams
- exercising moderately for at least 30 minutes most days of the week
- limiting alcohol to two drinks a day for men, one a day for women
- cutting caffeine
You may also need medication to help you stay below 130/80. Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers can help lower blood pressure and have a protective effect on the kidneys by reducing protein in your urine and slowing kidney damage.