You can have high blood pressure (hypertension) for years without a single symptom. But silence isn't golden. Uncontrolled high blood pressure increases your risk of serious health problems, including heart attack and stroke. Blood pressure is determined by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. The more blood your heart pumps and the narrower your arteries, the higher your blood pressure. High blood pressure typically develops without signs or symptoms. And it affects nearly everyone eventually. If you don't have high blood pressure by age 55, you have a 90 percent chance of developing it at some point in your life, according to the National Heart, Lung, and Blood Institute. Fortunately, high blood pressure can be easily detected. And once you know you have high blood pressure, you can work with your doctor to control it.