High blood pressure makes your heart work harder and, over time, can damage blood vessels throughout your body. If the blood vessels in your kidneys are damaged, they may stop removing wastes and extra fluid from your body. The extra fluid in your blood vessels may then raise blood pressure even more. It's a dangerous cycle.

High blood pressure is one of the leading causes of kidney failure , also commonly called end-stage renal disease (ESRD). People with kidney failure must either receive a kidney transplant or go on dialysis. Every year, high blood pressure causes more than 25,000 new cases of kidney failure in the United States.

Most people with high blood pressure have no symptoms. The only way to know whether your blood pressure is high is to have a health professional measure it with a blood pressure cuff. The result is expressed as two numbers. The top number, which is called the systolic pressure, represents the pressure when your heart is beating. The bottom number, which is called the diastolic pressure, shows the pressure when your heart is resting between beats. Your blood pressure is considered normal if it stays below 120/80 (expressed as "120 over 80"). People with a systolic blood pressure of 120 to 139 or a diastolic blood pressure of 80 to 89 are considered prehypertensive and should adopt health-promoting lifestyle changes to prevent diseases of the heart and blood vessels. If your systolic blood pressure is consistently 140 or higher or your diastolic pressure is 90 or higher, you have high blood pressure and should talk with your doctor about the best ways to lower it.

Kidney damage, like hypertension, can be unnoticeable and detected only through medical tests. Blood tests will show whether your kidneys are removing wastes efficiently. Your doctor should order tests to measure your serum creatinine. Having too much creatinine in your blood is a sign that you have kidney damage. The doctor should use the serum creatinine to estimate the main kidney function called glomerular filtration rate, or GFR.

Another sign is proteinuria, or protein in your urine. Proteinuria has also been shown to be associated with heart disease and damaged blood vessels.