High blood pressure—also known as hypertension—is a condition that increases the risk for heart attack, stroke, kidney failure, coronary heart disease, and other serious health problems. Blood pressure is the force of blood pushing against the inside walls of arteries. The harder your heart pumps and the narrower your arteries are, the higher your blood pressure rises. Over time, the wear and tear caused by untreated high blood pressure can damage your blood vessels and vital organs.