By utilizing the basic principles of hemodynamics and hydraulics, research suggests that fluid retention is detrimental for the cardiovascular system because it increases the likelihood of turbulent blood flow, regardless of whether or not blood pressure is raised. Increased turbulence promotes endothelial dysfunction, thereby contributing to the development of atherosclerotic cardiovascular disease. Fluid retention induces hypertension in some individuals, increases stroke volume (the amount of blood that is ejected by the heart with each contraction) in others, and causes edema. Some blood pressure lowering medications also increase stroke volume and cause edema but prevent heart attacks and strokes when used to treat hypertension. For drugs that increase the risk of adverse cardiovascular events, it may be possible to reduce or neutralize the increased risk by simultaneous diuretic administration.
Original Article: Clinical Hemorheology and Microcirculation (free pdf)