Left ventricular hypertrophy (LVH) may be physiological or pathological. Only pathological LVH has been shown to be a risk factor for cardiovascular events. LVH may not be homogeneous. It seems to progress from muscle hypertrophy to eventual cell death and myocardial fibrosis. Potential for reversal of LVH may therefore depend on the stage at which it has been attempted. An interaction between LVH and serum potassium levels could have important therapeutic implications, particularly with regard to the use of thiazide diuretics as long-term treatment for hypertension.