A medical condition in which the blood pressure is permanently (chronically) elevated. Persistent hypertension is one of the risk factors for strokes, heart attacks and heart failure, and is a leading cause of chronic kidney (renal) failure. Beginning at a systolic pressure of 115 mmHg and a diastolic pressure of 75 mmHg (commonly written as 115/75 mmHg), cardiovascular disease risk doubles for each increment of 20/10 mmHg. A normal blood pressure is 90–119/60–79 mmHg.