BackgroundHypertension guidelines indicate accurate diagnosis and appropriate therapy with drug treatment. 1 Medication to treat hypertension may have shortcomings, so it would be ideal to have alternative treatments to lower blood pressure (BP) without modifying the natural equilibrium of the body. One example is long-term heated water-based exercises which have a relatively persistence effect. 2 The possibility of achieving similar results by permanently applying external magnetic fields is very attractive.Early attempts applying magnetic fields to patients reported some positive results, [3][4][5][6] but the permanent magnets used in the past were large in size and weak in intensity. Nowadays, low-cost strong permanent magnets are commercially available. 7 In vitro measurements using human blood circulating inside glass tubes detected a decrease in viscosity when exposed to oriented magnetic fields: 8 this could lead to increased fluidity and possibly a decrease in BP.We do not consider other related aspects such as the elasticity of the arteries 9,10 or the effect of the magnetic field gradients on blood cell circulation. 11 Other studies trying to establish the influence of magnetic fields on workers operating magnetic resonance imaging equipment are beyond our line of investigation, since those magnetic fields are inhomogeneous, not