We all know that exercise and even agitation can raise your blood pressure. Conversely, a peaceful nights sleep should bring it down-as much as 10 to 20 percent for healthy adults. However, many people with hypertension find their that blood pressure doesnt dip overnight. And that can be a major contributor to serious cardiovascular and kidney problems. "Optimal control of blood pressure is important at all times," says Cleveland Clinic cardiologist and hypertension specialist Fetnat Fouad-Terazi, MD. "It helps prevent atherosclerosis and retards the progression of renal disease."