High blood pressure is the primary cause of death among Americans older than 25. About 75 million people suffer from high blood pressure or hypertension, which is a major risk factor for heart disease. Blood pressure tends to increase with weight gain and age. It is not known why obesity is a major cause of high blood pressure. However, research has shown that obese patients displayed an increase in blood volume and arterial resistance. For people who are overweight and have high blood pressure, losing as little as 8 pounds can help reduce blood pressure to a safe level.