Hypertension is the force of blood pushing against the walls of the arteries. It is measured as systolic pressure when the heart beats and pumps blood and as diastolic pressure in the arteries when the heart rests between beats. There are 4 stages in blood pressure classification—normal, prehypertension, stage 1, and stage 2. Hypertension affects approximately 50 million people in the United States and 1 billion people worldwide. People who are normotensive at age 55 years have a 90% chance of developing hypertension in their lifetime. Starting with a blood pressure of 115/75 mmHg, the risk of cardiovascular death doubles with each 20/10 mmHg increment...
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